Albert Barnes Commentary 2 Kings 17:27

"Then the king of Assyria commanded, saying, Carry thither one of the priests whom ye brought from thence; and let them go and dwell there, and let him teach them the law of the god of the land." — 2 Kings 17:27 (ASV)

Carry one of the priests ...; let them go and dwell there, and let him teach - The double change of number is curious, but the text needs no emendation. The priest would require to be accompanied by assistants, who would “go and dwell,” but would not be qualified to “teach.” The mysteries of the worship would be known to none except the priests who had ministered at the two national sanctuaries of Dan and Bethel.