After leaving Egypt, Moses and his gang went on a lot of wacky adventures. At some point Moses took it upon himself to try his hand at mountain climbing. When he got to the top of Mount Sinai he received the Decalogue, as well as some other words of wisdom. But from whom did he receive the law? The bible gives us two answers from which to choose.
But when Paul recounted this story to the Galatians, we get a different answer. In verse 3:19 Paul says that Moses (as the “mediator”) was given the law by angels.
This is a striking contradiction because Galatians is a book of the New Testament. Paul should’ve had a copy of Exodus at his fingertips. He could’ve easily cross-referenced his own work with the Old Testament, but for whatever reason he didn’t.