Boyd’s Bible Dictionary:
(barbed). Badge of manhood. Tearing, cutting, or neglecting, a sign of mourning (Ezra 9:3, Isa. 15:2; 50:6; Jer. 41:5; 48:37). To insult it a gross outrage (2 Sam. 10:4). Taken hold of in salutation (2 Sam. 20:9). Removed in leprosy (Lev. 14:9).
Concise Bible Dictionary:
The Israelites always cultivated the beard, and highly valued it. The law forbade them to “mar the corners of their beards” (Lev. 19:27), and a priest must not shave off the corner of his beard as a sign of mourning (Lev. 21:5). King Hanun inflicted a sore indignity when he marred the beards of David’s ambassadors (2 Sam. 10:4). Ezra in great grief at the sin of the people plucked off the hair of his head and of his beard (Ezra 9:3: Compare. Jer. 41:5). God’s judgment on Israel is compared to the beard being consumed by a razor, (Isa. 7:20); and they were to be scattered as hair that is cut off (Ezek. 5:1, 2, 12). Of Moab it was said, every beard should be cut off (Isa. 15:2; Jer. 48:37).
Strong’s Dictionary of Hebrew Words:
Meaning:
from 8193; the beard (as a lip-piece)
KJV Usage:
beard, (upper) lip
From Manners and Customs of the Bible:
Micah 3:7. Then shall the seers be ashamed, and the diviners confounded: yea, they shall all cover their lips; for there is no answer of God.
The margin has “upper lip,” that is, the lip-beard or mustache, as the word sapham is rendered by Gesenius and others. The Hebrews held the beard in high estimation as a mark of manliness. To cover the lip, and thus conceal the beard growing there, was a sign of sorrow or of mourning.
Thus, in the text, Micah represents the prophets as mourning because God refuses to reveal himself to them: “they shall all cover their lips.” Thus also the leper was required to cover his upper lip (Lev. 13:45). An allusion to this custom is likewise made in Ezekiel 24:17, 22.