Phone Number

When you want to get in contact with someone, you ask them for their phone number. If they like you they give it to you. Now you can hook up with them whenever you want. A mitzvah is G-d's phone number. He told us how to get in touch with him. If you change a phone number because you don't like the sound of it, let's say substitute a nine for a seven, then you don't get the same person anymore. That's why the details of the mitzvot are so important.