Exodus 4:27

And the Lord said to Aaron, Go into the wilderness to meet Moses. This showed that the favor of the Lord had once more turned to Moses. His wife was not in full accord with him and his belief at that time, but Aaron's coming would be a great comfort to him. And he went, and met him in the mount of God, on Mount Horeb, and kissed him, this cordial greeting being all the more natural since the brothers had not seen each other for about forty years.