God has better grammar than that

There's a billboard I see on my way home from work everyday that's starting to annoy me. It's one of those stupid, black-with-white-text billboards that presumes to have quotes from God on it. "If you don't stop using my name in vain, I'll make rush hour longer," is one example.

That's annoying enough, but this particular one says "What part of 'Thou Shall Not' didn't you understand?" Oh, I dunno, perhaps the improper conjugation? Perhaps if it said 'Thou Shalt Not' like it was supposed to, then I wouldn't have been coveting my neighbor's wife this whole time.