The same came to him by night, and said to him, "Rabbi, we know that you are a teacher come from God, for no one can do these signs that you do, unless God is with him."
Except God be with him - Except God aid him, and except his instructions are approved by God. Miracles show that a prophet or religious teacher comes from God, because God would nor work a miracle in attestation of a falsehood or to give countenance to a false teacher. If God gives a man power to work a miracle, it is proof that he approves the teaching of that man, and the miracle is the proof or the credential that he came from God.