God is not man, that he should lie, or a son of man, that he should repent. (Numbers 23:19)
He wasn't (a man) at the time.
That's weak. He was still God at the time.
He wasn't (a man) at the time.
I would suggest that conjugations of the verb "to be" carry a little more meaning when applied to God than to man.
And God said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you. (Exodus 3:14)