“the sons of the Anakim there.” Anak was a “Fallen One,” one of the Nephilim. His father was Arba (Josh. 15:13), and his descendants were the Anakim. The term “Anakim” comes from Anak, the son of Arba, and Deuteronomy 1:28 is the first use of “Anakim” in the Bible (cp. Deut. 2:10, 11, 21; 9:2; Josh. 11:21, 22; 14:12, 15).
[For more on the Nephilim, see commentary on Genesis 6:4.]