'Swear to Me' in the Bible

so now, swear to me here by God that you will not deal unfairly with me [by breaking any agreements we have] or with my son or with my descendants, but as I have treated you with kindness, you shall do the same to me and to the land in which you have sojourned (temporarily lived).”

Jacob said, “Swear [an oath] to me today [that you are selling it to me for this food]”; so he swore [an oath] to him, and sold him his birthright.

Then he said, “Swear to me [that you will do it].” So he swore to him. Then Israel (Jacob) bowed in worship at the head of the bed.