It talks at length about 'sexual immorality' and resisting urges but seldom calls out masterbation specifically.

Really just Leviticus 15:16-17 where it is called unclean, but only if you ejaculate so there might be a gooning loophole if you want to be a jew about it.

Matthew 5:28 if you can pull it off without thinking of a woman who isn't your wife you're in the clear

Genesis 38:8-10 pulling out is a sin (taking things out of context is fun)