עַל־שֶׁ֥בֶר בַּת־עַמִּ֖י הָשְׁבָּ֑רְתִּי קָדַ֕רְתִּי שַׁמָּ֖ה הֶחֱזִקָֽתְנִי׃
For the hurt of the daughter of my people am I seized with anguish; I am black, appalment hath taken hold on me.
Rashi on Jeremiah
I mourn lit. I am darkened, an expression of blackness and darkness.