Strange customs

I've been given the task of reading thru the whole bible in 2 yrs. I'm a little behind but I was reading thru Genesis not too long ago.

I just thought this was funny... In Genesis 24:2 (and 24:9) and then again in 47:29, there are two people... one asking the other to make a promise to them. It's just really funny cos the way the promise was made was by the person putting their hand under the other person's thigh... how strange is that...

I was just thinking... i'm glad that custom hasnt been passed on...
like could u imagine it now: "hey put ur hand under my thigh and promise me this...."
or at a wedding: "i put my hand under ur thigh and promise...."
or in a courtroom: "i promise to tell the truth..." actually how would that work??