Wiktionary
vb. (context idiomatic English) To act self-righteous in accusing another person, believing that one is blameless.
Wikipedia
Cast the First Stone was the second full-length album by New Jersey, U.S. band Ensign. It was released by Nitro Records in March, 1999 and follows the band's debut, Direction of Things to Come which came out on Indecision Records in November, 1997.
Usage examples of "cast the first stone".
When he invites the Pharisees to cast the first stone, when he asks whose image is ob the coin to be paid in tribute, when he plays on words and says ‘.
I'd like to believe that a God-fearing man such as Reverend Barnett would refuse to use such tactics, and I'm certainly not going to cast the first stone.
I was pretty sure which one of us had elected herself to cast the first stone.
The Scriptures say, 'Let him who is without sin cast the first stone.