Moses
Numbers 33:4ESV·traditional attribution

while the Egyptians were burying all their firstborn, whom the LORD had struck down among them. On their gods also the LORD executed judgments.

John Gill Reformed Baptist @doctorgill

For the Egyptians buried all their firstborn, which the Lord had smitten among them,.... Which contributed much to the more easy and safe deliverance of the children of Israel; for their hearts were heavy with sorrow, and their hands were full, and they had other work to do, namely, to bury their dead, than to molest Israel; and besides, they knew it was for detaining...

Jamieson-Fausset-Brown Reformed @jfbcommentary

upon their gods--used either according to Scripture phraseology to denote their rulers (the first-born of the king and his princes) or the idolatrous objects of Egyptian worship.

Geneva Bible Notes Reformed @genevanotes

For the Egyptians buried all [their] firstborn, which the LORD had smitten among them: upon their gods also the LORD executed judgments. (b) Either meaning their idols, or their men of authority.