The soft curly hair that forms the fleece of certain animals, particularly sheep. It was shorn and used extensively by the Hebrews and others of ancient times to make clothing and for doing embroidery. (Ex 35:4-6, 25; 36:8, 35, 37; 38:18; 39:1-8, 22-29; Le 13:47; Pr 31:13, 22; Eze 34:3) Woolen clothing provides insulation from heat and cold and is comfortable, imparting warmth without great weight and absorbing moisture though not feeling damp to the wearer.

Under the Law, the Israelites were required to give “the first of the shorn wool” of their flocks to the priests. (De 18:3-5) The people who were not priests were forbidden to “wear mixed stuff of wool and linen together.”​—De 22:11; Le 19:19; see CLOTH (Other Uses).

The importance of wool in ancient times is indicated by the fact that Moabite King Mesha paid “a hundred thousand lambs and a hundred thousand unshorn male sheep” to the king of Israel as tribute. (2Ki 3:4) Wool was also a valuable item of trade.​—Eze 27:1, 2, 7, 16, 18.

Since wool is often white in its natural state, it is sometimes associated with whiteness and purity. For example, through the prophet Isaiah, Jehovah likened forgiven sins to white wool, saying: “Though the sins of you people should prove to be as scarlet, they will be made white just like snow; though they should be red like crimson cloth, they will become even like wool.”​—Isa 1:18-20.

Jehovah gives “snow like wool,” blanketing the land as with a warm covering of white wool.​—Ps 147:16.

“The Ancient of Days,” Jehovah God, is depicted symbolically in vision as having hair like clean wool. (Da 7:9) This suggests great age and wisdom, which are associated with gray-headedness. (Compare Job 15:9, 10.) Similarly, the apostle John saw “someone like a son of man” and observed that “his head and his hair were white as white wool, as snow.” (Re 1:12-14) His hair being described in this manner may indicate that it had become white in the way of righteousness.​—Pr 16:31.