According to the Book of Numbers, during the conquest of Canaan by the Israelites, Anak (^{[pronunciation?]}; Heb. 'nq spelt as both ענק and as הענק depending upon the reference) was a well-known figure, and a forefather of the Anakites (Heb. Anakim) who have been considered "strong and tall," they were also said to have been a mixed race of giant people, descendants of the Nephilim (Numbers 13:33). The use of the word "nephilim" in this verse describes a crossbreed of God's sons and the daughters of man, as cited in (Genesis 6:1-2) and (Genesis 6:4). The text states that Anak was a Rephaite (Deuteronomy 2:11) and a son of Arba (Joshua 15:13). Etymologically, Anak means [long] neck.

The sons of Anak are first mentioned in Numbers 13. The Israelite leader Moses sends twelve spies representing the twelve tribes of Israel to scout out the land of Canaan, and give a full report to the congregation. The spies enter from the Negev desert and journey northward through the Judaean hills until they arrive at the brook of Eshcol near Hebron, where reside Sheshai, Ahiman, and Talmai, the sons of Anak. After the scouts have explored the entire land, they bring back samples of the fruit of the land; most notably a gigantic cluster of grapes which requires two men to carry it on a pole between them. The scouts then report to Moses and the congregation, that "the land indeed is a land flowing with milk and honey," but ten of the twelve spies discourage the Israelites from even attempting to possess the land, for they reported that the men were taller and stronger than the Israelites, and moreover the sons of Anak dwell in the land, and that they felt like grasshoppers in their presence.