Gen_35:21. Jacob's first halting place between Bethlehem and Hebron was "beyond" this. The name means "a flock" or "drove." The tower was to watch the flock against wild beasts or robbers. Jewish tradition made it the destined birthplace of Messiah. Jerome saw in it the foreshadowing of the announcement of His birth to the "shepherds." Probably the Tower of Edar answers to the present Khirbet Sir el Ghanem, "the ruin of the sheepfold," which however contains Christian remains, arches, cisterns, tombs, etc.
Fausset's Bible Dictionary
By Andrew Robert Fausset, co-Author of Jamieson, Fausset and Brown's 1888.
E'dar, Tower of. (more accurately Eder, a flock). A place named only in Gen_35:21. According to Jerome, it was one thousand paces from Bethlehem.
Smith's Bible Dictionary
By Dr. William Smith.Published in 1863