מלכים ב יז:לג פירוש: רש״י

As was the custom of the nations from which they had been exiled. Those deities that are worshiped by the nations whom Sancheiriv and his armies had exiled (these) from there, they would worship here.³⁶Alternatively, כמשפט הגוים refers to some of the Bnei Yisroel who also worshiped idols while worshiping God.—Radak