Kommentar zu Tehillim 136:17

great kings Here he alluded to the thirty-one kings, and he compared for them Pharaoh and his host and the plagues of Egypt to mighty kings, harsher than they. Sihon was equal to all of them, [and Og was equal to all of them (Machzor Vitry)], each one individually, and so did he explain above (135: 11): “Sihon the king of the Amorites and Og the king of Bashan and all the kingdoms of Canaan.” So it is in the Aggadah.