"The evidence is that ordinary Jews in the first century used the divine name in the form Yaho. It is natural to assume that Jesus used the divine name whenever the occasion arose, unless there is evidence to the contrary. There is no record in the NT that Jesus subscribed to any superstition that the divine name was to be avoided."
You really are indeed a funny guy with a real WTS ant colony mentality :D ΙΑΩ was not his original reading of the Septuagint, but in all probability that of a marginal heterodox Jewish sect. For mainstream Judaism associated with the Jerusalem temple cult and the Sanhedrin, the everyday "use" of YHWH was completely forbidden.
While the name Yahweh is not Yahweh himself, in the Scriptures the "name" often represents the thing expressed by the name, and thus "the name of Yahweh" refers to Yahweh himself, who cannot tolerate any kind of profanation of his person. The pious can be characterized as those who fear the name of Yahweh. In fact, any violation of God's commandments is a desecration of his name. The often apostate Israel, therefore, brought disgrace upon the name of Yahweh with every sinful act. This is why the prophets often rebuked Israel for the desecration of Yahweh's name, most sharply Amos, Jeremiah, Ezekiel and Malachi.
Under such circumstances, the belief gained ground that the name of Yahweh should really be relegated to the sanctuary as the most appropriate environment, because only the consecrated personnel, the priesthood, could use it without profanation. The command given to the priests to invoke the name of Yahweh upon the sons of Israel during the blessing (Numbers 6, 27), seemed to confirm that only they were entitled to pronounce the name of Yahweh.
Under the influence of this increasingly widespread view, after the Babylonian captivity, out of respect for the sanctity of the name of Yahweh and to avoid profanation, a custom developed among the Jews to utter this sacred name less and less, then to write it less frequently in ordinary, profane documents (e.g. contracts), and finally not to utter or write it at all. According to the scholars (rabbis), this outcome sufficiently protected the name of Yahweh from profanation.
The practice of refraining from the use of the name Yahweh, or of increasingly withdrawing it from common use, can be observed from the beginning of the 3rd century BC. Philo of Alexandria (20 BC – AD 54), knowing nothing of the former general use of the name Yahweh, is evidence that the replacement of the name Yahweh with Adonai was probably already a completed fact in the 3rd century BC. The advice Ben Sirach, who lived in Jerusalem at the beginning of the 2nd century BC, which we read in Ecclesiasticus 23:9, points to this: "Do not accustom your mouth to oaths nor habitually utter the name of the Holy One".
Witnesses to the avoidance of the use of the divine name Yahweh include:
The earliest translation of the Old Testament Scriptures, the Alexandrian Greek translation known as the Septuagint (LXX), which was made in the 3rd century BC, always replaces the name Yahweh with the word Kyrios (= Lord).
Philo, an Alexandrian Jewish philosopher (died AD 54), possibly of priestly descent, writes that the four-letter divine name engraved on the high priest's golden head plate could only be uttered in the holy place (the temple) by those whose ears and tongues had been purified by wisdom. Elsewhere he says that to address God, people are allowed to use the word "Lord".
Josephus Flavius (died around AD 100), a Jewish priest and historian, informs us that it is not permissible to speak of that name, i.e., it is not permissible to pronounce the name that God revealed to Moses.
Rabbi Abba Saul, who lived in the first half of the 2nd century AD, already declares anyone who dares to pronounce the name Yahweh as it is spelled to be excluded from eternal salvation. He therefore threatens the person with punishment in the afterlife. No earthly judge judges such a person; only blasphemy against Yahweh is punished by earthly courts. However, a legal scholar of the 4th century, Rab Chanin, relying on the authority of the famous Rab (died 247), declares: "Whoever hears the name of God (Yahweh) mentioned from someone's mouth is obliged to excommunicate him immediately."
Since the mere pronunciation of the name Yahweh has been classified as a deadly sin by the rabbis, this teaching about the name of God has become increasingly complex among the Jews (especially among the so-called "mystics"), because the name of Yahweh, holy above all, was almost equated with the divine essence. Philo and Onkelos believe that the mere pronunciation of Yahweh's name in Moses' book is forbidden. According to Onkelos, "Whoever pronounces the name of Yahweh, let him be killed, let the entire community stone him, both the newcomer and the native, when he pronounces the Name, let him be killed."
And it is a firm principle in Rabbinic law that while all other sins can be atoned for in this life, there is no atonement in this life for the desecration of Yahweh's name; neither repentance, nor the Day of Atonement, nor suffering can wipe it out, in fact only the death of the penitent can.
Since the distrustful and at the same time unreliable Eastern man, prone to lying due to his character, frequent swearing was also very common among the ancient Jews, and in the oath the name of God is invoked, it is natural that the danger of desecrating the name Yahweh was most often at the thoughtless swearing. Therefore, rabbinism has long referred the prohibition contained in Exodus 20:7 mainly to the oath. Philo exclusively understood it about the oath. Josephus Flavius also writes that the third commandment (according to Jewish calculation) prohibits us from swearing in any vain thing. Similarly Onkelos, whose targum translates this verse of the Hebrew text as follows: "Do not swear by Yahweh's name in vain, for Yahweh does not hold him guiltless who swears falsely by his name."
Since, therefore, the sin committed by the careless pronunciation of Yahweh's name could not be made good by any earthly atonement, the Jews in Christ's time, looking for a way out, deliberately avoided naming God Himself in the oath and only swore by the heaven, the earth, Jerusalem, their own head (life), mistakenly thinking, on the one hand, that such an oath is not binding, and on the other hand, that they thus avoid the desecration of the divine name, and can indulge in the bad habit of vain, thoughtless swearing with impunity. However, our Lord Jesus spoke out against this erroneous understanding and thoughtless swearing and showed his contemporaries that such an oath, not directly on the name of God, but indirectly, is in fact an oath to God, because it involves reference to God as the creator and lord of those things.
It is noteworthy that the first Christian witness who informs us that the Jews read the word Adonai instead of the four-letter divine name is Origen (185-254), who, among other things, writes: "There is an unutterable four-letter name, which is also written on the high priest's golden forehead plate, and it is pronounced Adonai, although this is not what is written in the four letters; in Greek, it is expressed with the word Kyrios."
Albert Pietersma takes issue with Howard's claim that "we can now say with almost absolute certainty that the divine name, יהוה, was not rendered by κύριος in the pre-Christian Bible". He holds that the Septuagint Pentateuch originally contained κύριος, and that the hebraizing insertion of the tetragrammaton in some copies can be seen as "a secondary and foreign intrusion into LXX tradition". Emanuel Tov states that "the writing of the Tetragrammaton in Hebrew characters in Greek revisional texts is a relatively late phenomenon."
Martin Rösel holds that the Septuagint used κύριος to represent the Tetragrammaton of the Hebrew text and that the appearance of the Hebrew Tetragrammaton in some copies of the Septuagint is due to a later substitution for the original κύριος: "By means of exegetical observations in the Greek version of the Torah, it becomes clear that already the translators of the Septuagint have chosen 'Lord' (kyrios) as an appropriate representation of the tetragrammaton; the replacement by the Hebrew tetragrammaton in some Greek manuscripts is not original." He recalls that, although κύριος was obviously the name that early Christians read in their Greek Bible, "Jewish versions of the Greek Bible, including Aquila and Symmachus as well as a few LXX manuscripts," had the Tetragrammaton in Hebrew letters or the form ΠΙΠΙ imitating Hebrew יהוה and also recalls the arguments for the originality of the Greek transcription ΙΑΩ. However, in view of the inconclusive nature of the analysis of the manuscripts, he proposes evidence internal to the Septuagint text that suggests that "κύριος is the original representation of the first translators", delimiting his research in this matter to the Pentateuch texts, since these were the earliest and provide a glimpse of a translator's theological thinking, for, as he said earlier, "the translators of the Septuagint were influenced by theological considerations when choosing an equivalent for the divine name". In some contexts, to avoid giving the impression of injustice or harshness on the part of κύριος, they represent the Tetragrammaton instead by θεός. Thus the immediate context explains the use of θεός as avoidance of the default translation as κύριος, while "it is hardly conceivable that later scribes should have changed a Hebrew tetragrammaton or Greek ΙΑΩ into a form of ὁ θεός". The presence of κύριος in the deuterocanonical books not translated from Hebrew but composed originally (like the New Testament) in Greek and in the works of Philo shows, Rösel says, that "the use of κύριος as a representation of יהוה must be pre-Christian in origin". He adds that this use was not universal among Jews, as shown by the later replacement of the original Septuaginta κύριος by the Hebrew Tetragrammaton; and he says that "the ΙΑΩ readings in the biblical manuscript 4QLXXLevb are a mystery still awaiting sound explanation. What can be said, is that such readings cannot be claimed to be original."
The Jews were not afraid of "superstitiously" pronouncing the name, but of unnecessary invocation of the Person behind it, reckless, insignificant, aimless, or malicious mention (the "in vain" in Exodus 20:7 refers to this). Understandably, due to their terrifying experiences with God, they avoided the "vain" use of God's name.
There is no indication in the Bible that Jesus ever uttered the name. The burden of proof would be on you, which you obviously don't do enough. This is speculation. I know that every time you see the word "name", you immediately associate it with the term YHWH, but this can even be supported by the publications of the Watchtower, that this term refers to the being of God. Hallowed be the "name" of God = Hallowed be God himself!
If Jesus in the synagogue (Luke 4:16-21) had pronounced the Name while reading Isaiah (61:1-2), wouldn't that have caused an outrage among the "superstitious" Jews, wouldn't they have attacked him immediately? Instead, we read that they listened attentively to the reading (4:20), and even initially received his added words positively (4:22).
I know that in the Witnesses' minds, the Watchtower's dozen hypotheses consolidate into fact.
The Hebrew Scriptures were translated into ancient Greek as early as the 3rd century BC (this is the Septuagint), and such translations were made later as well. However, all these translated the text of the Old Testament. Of course, it is acceptable that some translators retained the Tetragrammaton in the Greek translation (and here we are not talking about the original Greek text of the New Testament!).
However, it is already the unproven theory of the WTS, lacking any factual basis, that the writers of the New Testament, the Christian Greek Scriptures, using these Septuagint versions, also transferred it into the Greek text of the New Testament. Out of the 15 Old Testament quotes found in the New Testament, 14 directly come from the Hebrew Scriptures, yet there is not a single New Testament fragment that contains the Tetragrammaton!
However, most Witnesses, when they see the fragments of the Septuagint in the Appendix of the NWT or the image of the Hexapla fragment in this article, and the Association claims: this "proves that the name of God was used in the Christian Greek Scriptures," they automatically adopt and consider this baseless conclusion logical. Why? Simply because the complete system of the borrowed theory is already in their head, they trust the WTS, so this information, without any checking, ends up on the appropriate shelf of the existing system, in the box labeled "Evidence". The WTS manipulates extremely effectively. This is how a fiction becomes a fact, even a dogma, in their minds as well.
This is all you are doing, to bring out the YHWH associated with the Hebrew Old Testament cult, a Judaizing tendency that is completely foreign to the theological environment of the New Testament.