Seeing now that he is the oldest servant and the one most entrusted to rule over all Abraham had, it would appear that this is who this is. Now Abraham makes him swear that he will not take a wife from any foreign land, but must go back to Abraham’s family and find Isaac’s wife there. A couple of things to look at here. First, the way this oath is implemented. Placing the hand under the thigh was a Jewish practice that we see two different times in scripture. Here with Abraham and his servant, and again when Jacob had Joseph swear an oath regarding where he is to be buried.