Jeremiah 28:17

28:17 In the seventh month of that very same year ¹  the prophet Hananiah died.

Jeremiah 41:1

41:1 But in the seventh month ²  Ishmael, the son of Nethaniah and grandson of Elishama who was a member of the royal family and had been one of Zedekiah’s chief officers, came with ten of his men to Gedaliah son of Ahikam at Mizpah. While they were eating a meal together with him there at Mizpah,

[28:17]  ¹ sn Comparison with Jer 28:1 shows that this whole incident took place in the space of two months. Hananiah had prophesied that the captivity would be over before two years had past. However, before two months were past, Hananiah himself died in fulfillment of Jeremiah’s prophecy of his death. His death was a validation of Jeremiah as a true prophet. The subsequent events of 588 b.c. would validate Jeremiah’s prophesies and invalidate those of Hananiah.

[41:1]  ² sn It is not altogether clear whether this is in the same year that Jerusalem fell or not. The wall was breached in the fourth month (= early July; 39:2) and Nebuzaradan came and burned the palace, the temple, and many of the houses and tore down the wall in the fifth month (= early August; 52:12). That would have left time between the fifth month and the seventh month (October) to gather in the harvest of grapes, dates and figs, and olives (40:12). However, many commentators feel that too much activity takes place in too short a time for this to have been in the same year and posit that it happened the following year or even five years later when a further deportation took place, possibly in retaliation for the murder of Gedaliah and the Babylonian garrison at Mizpah (52:30). The assassination of Gedaliah had momentous consequences and was commemorated in one of the post exilic fast days lamenting the fall of Jerusalem (Zech 8:19).