Matthew Poole and continuators on Exodus 5:1

1 AND afterward Moses and Aaron went in, and told Pharaoh : Thus saith the LORD God of Israel, Let my people go, that they may hold a feast unto me in the wilderness.

And with them some of the Elders of Israel, as may seem from Exod. 3. 18. though here onely the two chiefs be mentioned. Or, because Moses did not seem to be satisfied with the assistance of the Elders before offered him, Exod. 3. 18 God was pleased to give him a more acceptable assistant in their stead even Aaron his brother, Exod. 4. 14.

Either both successively told him: Or Aaron did it immediately and with his tongue, Moses by his interpreter, and by his command.

Or, offer a sacrifice, as they express it, ver. 3. and chap. 10. 9. For both went together and a good part of many sacrifices was spent in feasting before the Lord and unto the honour of the Lord. See Deut. 12. 6, 7, 11, 12.