The hollow of Jacob's thigh was strained as he wrestled at Peniel (Ge 32:25), and to this is attributed the Jewish custom (enjoined in the Mishna) of not eating 'the sinew of the hip' (Ge 32:32). On the thigh the sword was girded (Ex 32:27; Ps 45:3; Song 3:8); Ehud's on the right thigh because he was left-handed (Jg 3:16,21). Under the jealousy ordeal the woman's thigh falls away if she has been guilty of adultery (Nu 5:21 ff.). To smite 'hip and thigh' (lit. 'leg upon thigh') is a phrase denoting utter discomfiture accompanied by great slaughter (Jg 15:8). Its origin is unknown, and its meaning much disputed. Is Jer 31:19 and Eze 21:12 smiting upon one's thigh is a gesture of sorrow or terror. In Heb. (cf. Authorized Version margin) of Ge 46:25; Ex 1:5; Jg 8:30 a man's children are described as coming out of his thigh. This explains the oath taken by placing the hand under the thigh (Ge 24:2,9; 47:29), a special sacredness being ascribed to the organs of generation. In NT 'thigh' occurs only in Re 19:16, where perhaps the meaning is that the name was written on that part of the garment which covered the thigh.
J. C. Lambert.