The ‘hand under the thigh’ oath was used when Abraham sent Eliezer to find a wife for Isaac. Joseph puts his hand under his father’s thigh symbolizing the covenant promise of descendants for Jacob. He wants Joseph to swear an oath that his bones will be taken back to his father’s land, the Land of Promise given to Abraham, and buried in the cave with his ancestors.
"Your eyes will see Jerusalem: A tent which will not be folded; its stakes will never be pulled up" (Isaiah 33:20).
