GRAVEL (חָצָץ, H2953, gravel, and מָעָה, H5054, grain [of sand]). Small pebbles.
חָצָץ, H2953, is used fig. in Proverbs 20:17 of a liar, showing the consequences of deceitfulness, and in Lamentations 3:16 of the Lord’s dealings with a sufferer (“He has made my teeth grind on gravel”). The plural of מָעָה, H5054, occurs in Isaiah 48:19, where RSV correctly trs. it as “gravel” (this once legitimate connotation of Eng. “gravel” is now obsolete).
International Standard Bible Encyclopedia (1915)
(chatsats, from root chatsats, "to divide." Kindred roots have the meaning of "to cut," "to hew," "to sharpen," hence chets, "arrow" (2Ki 13:17; Ps 64:7 and often); compare Arabic chacca, "to fall to the lot of," chiccah, "portion"): In Pr 20:17, we have:
"Bread of falsehood is sweet to a man;
But afterwards his mouth shall be filled with gravel."
And in La 3:16:
"He hath also broken my teeth with gravel stones; he
covered me with ashes."
The only other occurrence of the word is in Ps 77:17, where it is the equivalent of chets, "arrow" (see supra):
"The clouds poured out water;
The skies sent out a sound:
Thine arrows also went abroad."
Pr 20:17 and La 3:16 both suggest the frequent occurrence of grit in the coarse bread, the source of the grit being not necessarily the grindstone, but possibly even small stones originally mingled with the wheat and never properly separated from it.