Jeremiah 41:5
That there came certain from Shechem, from Shiloh, and from Samaria, even fourscore men, having their beards shaven, and their clothes rent, and having cut themselves, with offerings and incense in their hand, to bring them to the house of the LORD.
Jeremiah's prophecies after chapter 20 are not placed in chronological order, but the chapter itself makes its time clear. The verse stands in chapters 40 to 45, which in chronological order come after chapter 39. It belongs to the events following the fall of Jerusalem and is placed after Jeremiah 40 in the chronological order of the book.
That section concerns the Jews left in the land after Zedekiah's captivity and their flight into Egypt. Chapters 32 to 45 give the history of the two years before the fall of Jerusalem. Within that history belongs the portion containing prophecies uttered during the rule of Gedaliah.
The chapter records the assassination and murder of Gedaliah at Mizpah, the Jewish viceroy left in the land by the king of Babylon, Nebuchadnezzar, after the destruction of Jerusalem, and the scattering of the remnant of Jews left in the land. The verse records that eighty men from Shechem, from Shiloh, and from Samaria came with offerings and incense in their hand to bring them to the house of the Lord, mourning with shaven beards, torn clothes, and cuts on their bodies. After he had already killed Gedaliah, Ishmael killed seventy of those eighty men.
This tragedy was the reason for the fast observed in the seventh month. The event is commemorated by the Fast of Gedaliah on Tisri 3, one of four fasts commemorating events connected with the fall of Jerusalem. The fast begins at daybreak. Among the Jews, neglecting to trim or dress the beard was an expression of deep mourning, so trimming the beard is proper and not sinful, and no rule fixes how close it may be trimmed.