Jeremiah
Jeremiah 6:26BSB·traditional attribution

O daughter of my people, dress yourselves in sackcloth and roll in ashes. Mourn with bitter wailing, as you would for an only son, for suddenly the destroyer will come upon us.

John Calvin Reformed @genevareformer

The Prophet seems to use more words than necessary; for in a clear matter he appears to extend his discourse too far: but we must consider the design which has been mentioned; for he could not rouse the Jews without urging the matter on them with great vehemence. Known and sufficiently common is the term, “daughter of my people, “as applied to the whole community.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. God appeals to all the neighbours, nay, to the whole world, concerning the equity of his proceedings against Judah and Jerusalem (Jer 6:18, Jer 6:19): "Hear, you nations, and know particularly, O congregation of the mighty, the great men of the nations, that take cognizance of the affairs of states about you and make remarks upon them.

Commenting on Jeremiah 6:18-30

John Gill Reformed Baptist @doctorgill

O daughter of my people, gird thee with sackcloth,.... Either as a token of repentance for sin; so the king of Nineveh and his subjects did, to show their repentance, Jon 3:6 or as a sign of mourning, for the calamities coming on them, Gen 37:34. and wallow thyself in ashes; or roll thyself in them, as a token of the same.