E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
LAYING ON OF HANDS. The laying on of a bishops hands in confirmation or ordination.
PUTTING THE HAND UNDER THE THIGH. An ancient ceremony used in swearing.
And Abraham said unto his eldest servant Put, I pray thee, thy hand under my thigh: and I will make thee swear that thou shalt not take a wife unto my son of the daughters of the Canaanites.Genesis xxiv. 2, 3.