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.
And Abraham said unto his eldest servant of his house, that ruled over all that he had, Put, I pray thee, thy hand under my thigh:
And the servant put his hand under the thigh of Abraham his master, and sware to him concerning that matter.
And when he saw that he prevailed not against him, he touched the hollow of his thigh; and the hollow of Jacob's thigh was out of joint, as he wrestled with him.
Therefore the children of Israel eat not of the sinew which shrank, which is upon the hollow of the thigh, unto this day: because he touched the hollow of Jacob's thigh in the sinew that shrank.
These are the sons of Bilhah, which Laban gave unto Rachel his daughter, and she bare these unto Jacob: all the souls were seven.
And the time drew nigh that Israel must die: and he called his son Joseph, and said unto him, If now I have found grace in thy sight, put, I pray thee, thy hand under my thigh, and deal kindly and truly with me; bury me not, I pray thee, in Egypt:
And all the souls that came out of the loins of Jacob were seventy souls: for Joseph was in Egypt already.
And he said unto them, Thus saith the LORD God of Israel, Put every man his sword by his side, and go in and out from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour.
Then the priest shall charge the woman with an oath of cursing, and the priest shall say unto the woman, The LORD make thee a curse and an oath among thy people, when the LORD doth make thy thigh to rot, and thy belly to swell;
But Ehud made him a dagger which had two edges, of a cubit length; and he did gird it under his raiment upon his right thigh.
And Ehud put forth his left hand, and took the dagger from his right thigh, and thrust it into his belly:
And Gideon had threescore and ten sons of his body begotten: for he had many wives.
And he smote them hip and thigh with a great slaughter: and he went down and dwelt in the top of the rock Etam.
Gird thy sword upon thy thigh, O most mighty, with thy glory and thy majesty.
They all hold swords, being expert in war: every man hath his sword upon his thigh because of fear in the night.
Surely after that I was turned, I repented; and after that I was instructed, I smote upon my thigh: I was ashamed, yea, even confounded, because I did bear the reproach of my youth.
Cry and howl, son of man: for it shall be upon my people, it shall be upon all the princes of Israel: terrors by reason of the sword shall be upon my people: smite therefore upon thy thigh.