I just did some more research to find out more on the Targums. Very, very interesting. Three of them do refer to the oracles about Gog and Magog, but it is the Targum of Pseudo-Jonathan which has the most elaborate account and which most probably preserves fragments from the Book of Eldad and Modad. All three Targums mention three prophecies. Two refer to events in the near future in the wilderness, while the third relates to the distant "final days". Here is the relevant text of the oracles from Ps.-Jonathan:
"And the prophetic spirit rested on them. Eldad was prophesying and said: 'Behold, Moses shall be gathered from this world, and Joshua bar Nun shall be standing in his place and leading the people of the house of Israel and bringing them to the land of the Canaanites and giving them possession over it.' Medad was prophesying and said: 'Behold, quail came up from the sea and were covering the entire camp of Israel and shall become a stumbling-block to the people.' But the two prophesied as one and said: ' Behold, a king shall arise from the land of Magog at the end of days. He shall gather kings crowned with crowns, and prefects attired in silk clothes, and all the nations shall obey him. They shall prepare for war in the land of Israel against the sons of the exile. However, the Lord (qyrys) is near ('ytymws) them at their hour of distress, and all of them will be killed by a burning breath in a consuming fire that comes from beneath the Throne of Glory, and their corpses will fall on the mountains of Israel. Then all the wild animals and birds of heaven shall come and consume their bodies. And after this all the dead of Israel shall live and shall delight themselves with the good which was hidden from them from the beginning. Then they shall receive the reward of their labors" (Targum of Pseudo-Jonathan, Numbers 11:26).
It is unclear how much of this derives from the original Edad and Modad. While the apocalypse in the book likely followed the outline given here, it is difficult to see this as anything more than a paraphrase or summary of received tradition -- if it weren't for the single phrase which closely resembles the saying quoted by Hermas: "The Lord is near them at their hour of distress." There are several things curious about this sentence. One is the transliterated Greek words. There are two of them: qyrys, from kurios "lord", and 'ytymws, from hetoimos "ready, at hand". As discussed above, this demonstrates that the tradition reported by Ps.-Jonathan had come from an intermediate Greek source, possibly a translation of Eldad and Modad. The use of hetoimos instead of Hermas' engus also would not be unusual if Ps.-Jonathan's source represented an independent translation into Greek from a Semitic original. In either case, the original saying would have likely originated in Psalm 144:18 which in the LXX more closely resembles Hermas' version; cf. "The Lord is near (engus kurios) to those who call upon him (epikaloumenois)". The linkage between prayer and the "drawing near" of the Lord (attested in Hermas) is also implicit in this verse. The other interesting thing about the sentence in Ps.-Jonathan is its ill-fit in the present context. The "them" in the sentence does not serve as the antecedent for the ones killed by the Lord in the next clause -- it instead refers to the "sons of the exile" that the Lord defends against the hoards of Magog. The appearance is thus that sentence in question is a fixed expression inserted imperfectly into the present context which reads much better without it.
The oracle itself is clearly derived from Ezekiel 37-39. The reference of fire being brought on the armies of Magog belongs to Ezekiel 39:6, the description of corpses falling on the mountains and being consumed by animals and birds is found in Ezekiel 39:4, and the resurrection of the dead builds on the reviving of the dead in Ezekiel 37. It is interesting that Revelation too draws heavily on Ezekiel in its latter chapters, in much the same order: (1) revival of dry bones / the first resurrection (Ezekiel 37:10; Revelation 20:5), (2) the restored kingdom / the reign of the holy ones for one thousand years (Ezekiel 37:21; Revelation 20:4), (3) Gog of Magog battle the holy ones (Ezekiel 38:2; Revelation 20:8), (4) the birds gorge on the dead bodies (Ezekiel 39:4; Revelation 19:21), (5) the prophet is taken up to a high mountain (Ezekiel 40:2; Revelation 21:10), (6) the Temple/City is measured (Ezekiel 40:5; Revelation 21:15), (7) the Temple is the seat of God's glory (Ezekiel 43:2; Revelation 21:23), the river of life and the trees with healing leaves (Ezekiel 47:12; Revelation 22:2). This raises the question of how much the apocalypse in Eldad and Modad resembled Revelation. It is usually agreed among critics that Revelation incorporates an older Jewish apocalyse, so Revelation's historical relation to Eldad and Modad would be a fascinating question should a manuscript for Eldad and Modad ever turn up. Revelation already shows intriguing links with 2 Baruch and 1 Enoch.
The description of Eldad and Modad's end-times prophecy is much shorter in the Targum Neofiti, but it has some rather important details:
"At the very end of days God and Magog ascend on Jerusalem, and they fall at the hand of King Messiah, and for seven years the children of Israel shall kindle fires from their weapons, and they will not have to go out to the forest" (Targum Neofiti, Numbers 11:26).
Here the warrior-king who defeats the Gentile barbarians is called "King Messiah". There is also a strange remark about the restored Israel being able to use their weapons to produce fires for a seven-year period. It is impossible to tell how much of this is independent tradition or derives from our Eldad and Modad. Taking both texts together, it is clear that such prophetic speculation was popular during the day, as several Dead Sea Scrolls oracles discuss the attack of Gog and Magog and their destruction at the hands of the messianic deliverer:
"[The Branch of] David will appear in the Last [Days ... He will defeat] his enemies and God will support him with a [spirit of] strength [...] and God will give him a throne of glory, a [sacred] crown, and elegant garments.... [He will put a] scepter in his head and he will rule over all the Gentiles, even Magog [and his army, all] the peoples his sword will control....He stretched out his hand against them and struck them so that the mountains shook and the corpses lay like garbage in the middle of the streets" (4Q161-162 2:9).
"You shall not turn back until the annihilation of the guilty ... so that they know that [you are God when you] carry out judgments on Gog and on all his company that are assembled about us....Lay your hand upon the neck of your enemies and your feet upon the backs of the slain. Crush the nations, your adversaries, and may your sword devour guilty flesh. Fill your land with glory, and your inheritance with blessing" (1QM 11:10-11, 15-17; 12:11-12).
Although none of these texts are dependent on the texts under discussion (and vice versa), they contain clusters of motifs which recur in the Targum passages. It is interesting that the Gog and Magog attack placed at the "end of days" in the Eldad and Modad prophecy is positioned in Revelation 20:8 after the first resurrection and after the thousand-year messianic kingdom. Such a two-stage eschaton is also mentioned in the Rabba: "Elijah was hidden and he will not be seen again until King Messiah comes. And the he will be seen but will be hidden a second time, and seem again only when Gog and Magog come" (Seder Olam Rabba, 17). It's too bad the apocalypse is no longer extant, it would make for an interesting comparison. There is one important motif in the Targum of Ps.-Jonathan which can be traced to pseudepigraphal literature; in referring to the armies of Magog, it states that "all of them will be killed by a burning breath in a consuming fire". This is exactly what is described in the sixth vision of 4 Ezra:
"And I looked and behold, that man flew with the clouds of heaven (i.e. the Son of Man figure from Daniel); and wherever he turned his face to look, everything under his gaze trembled, and whenever his voice issued from his mouth, all who heard his voice melted as wax melts when it feels the fire. After this I looked, and behold, an innumerable multitude of men were gathered together from the four winds of heaven (i.e. the armies of Magog) to make war against the man who came up from the sea (i.e. the Messiah)....When he saw the onrush of the approaching multitude, he neither lifted his hand nor held a spear or any weapon or war; but I saw how he sent forth from his mouth as it were a stream of fire, and from his lips a flaming breath, and from his tongue he shot forth a storm of sparks. All these were mingled together, the stream of fire and the flaming breath and the great storm, and fell on the onrushing multitude which was prepared to fight, and burned them all up" (4 Ezra 13:3-11).
Another interesting thing about the Targum of Ps.-Jonathan is that it inserts some biographical details about Edad and Modad: "They were the sons of Elisaphan bar-Parnak. Jochebad, daughter of Levi, gave birth to them for him at the time when Amram her husband divorced her and to whom she was married before she gave birth to Moses". This is the sort of "background information" that can be expected from a pseudepigraphon that represents a haggadaic expansion of a bare OT passage; however, the information may well derive from some other source. As for the pseudepigraphon itself, it was listed in the Stichometry of Nicephorus and was described as only 400 stichoi in length. By comparison, 1 Enoch was described as 4800 stichoi in length, the Testaments of the Twelve Patriarchs was 5100 long, and the Assumption of Moses occupied about 1400 stichoi. Eldad and Modad was therefore a very short book, comparable to the length of the epistle of James. In this vein, it is interesting that in the same section that mentions Eldad and Modad, Hermas reports that an old woman bestowed on him a "little book" (biblidion), beseeching him to transcribe it, and Hermas says that he copied the book letter by letter in unical form (Vis. 2.1.3-4). Although this episode could rightly be dismised as a literary device, it is curious that Hermas goes on to interpret the contents of this book and this is where he quotes from Eldad and Modad and starts using language shared with James and the apocryphal quotations of 1 and 2 Clement.