20 Furthermore, he carried off those remaining from the sword captive to Babylon, and they came to be servants to him and his sons until the royalty of Persia began to reign;
21 to fulfill Jehovah's word by the mouth of Jeremiah, until the land had paid off its sabbaths. All the days of lying desolated it kept sabbath, to fulfill seventy years. (2 Chr. 36:20, 21)
Jeremiah prophesied that “these nations [including the Judahites] will have to serve the king of Babylon for seventy years” (Jer. 25:11). The seventy years could be viewed as a full generation (cf. Jer. 27:7). Included in the seventy years is the desolation of the land, paying off its sabbaths (2 Chron. 36:21). The desolation did not last seventy years but fulfilled seventy years [until their seventy year servitude had been completed]. In Zechariah’s case, the cities had been denounced for seventy years, i.e., they had lost God’s protection (cf. Zech. 1:12).
According to Dan. 9:2 Jerusalem's devastation amounted to seventy years. Daniel would have known Jerusalem was not devastated for seventy years. The MT is corrupted in this instance. This was first century Jewish though on the matter. The concept, seventy years of desolation for Jerusalem, reflects later Rabbinic interpretation (see Dan. 9:2 Theo and Josephus). Devastations vs. reproach. In the OG we have ὀνειδισμός, meaning “reproach” (singular). See NETS. This is viewed as an error in the transmission: Jer. 25:9 καὶ εἰς ὀνειδισμόν and (I turn them) into a disgrace ולחרפות is read for MT and (I will turn them) into desolations. However, as seen, Dan. 9:2 is not drawn from Jer. 29:10, but Jer. 25:9-12. Here it could mean “reproach, disgrace, insult” (cf. Jer. 18:16; 19:8; Ezek. 5:13, 14). Specifically Jer. 25:9, and something to whistle at and places devastated to time indefinite.” LXX καὶ εἰς ὀνειδισμόν. See BHS footnote. KBLex, in accordance with the textcritical note suggests an emendation to (“as a disgrace”). See J. Lust, E. Eynikel & K. Hauspie (2003). A Greek-English Lexicon of the Septuagint: Revised Edition. Deutsche Bibelgesellschaft: Stuttgart. According to secular chronology, Jerusalem did not lie desolate for seventy years, but her reproach and humiliation could have started with Jehoiakim’s three year Babylonian servitude, completing Jeremiah’s seventy year cycle (2 Kings 24:1, 2; cf. Is. 25:9, 11). See also Dan. 9:16.