password brain teaser

Today’s Braingle brain teaser was a good one. Incidentally, if you like brain teasers, they have some good ones.

Here’s the teaser:

A man wanted to encrypt his password but he needed to do it in a way so that he could remember it. His password is 7 characters long. The password consists of letters and numbers only (no symbols like ! or <). In order to remember it he wrote down "You force heaven to be empty" Can you guess what his password is? I think the reason I liked it so much is because 1) I got it right away, and 2) I like seeing passwords like this because it helps when I'm creating a new one for myself. If you've figured it out, or you just want to know the solution, here's the answer.