Albert Barnes Commentary Exodus 4:14

"And the anger of Jehovah was kindled against Moses, and he said, Is there not Aaron thy brother the Levite? I know that he can speak well. And also, behold, he cometh forth to meet thee: and when he seeth thee, he will be glad in his heart." — Exodus 4:14 (ASV)

Anger - The words of Moses (Exodus 4:13) indicated more than an awareness of weakness; they showed a degree of vehemence and stubbornness.

Aaron - This is the first mention of Aaron. The words he can speak well probably imply that Aaron had both the ability and the willingness to speak. Aaron is here called the Levite, perhaps with reference to the future consecration of this tribe.

He cometh forth - That is, he is about to set out. Not that Aaron was already on the way, but that he had the intention of going to his brother, probably because the enemies of Moses were now dead .