Comentario sobre II Reyes 10:6

The sons of the king [number] seventy men, and the great men of the city, etc. All this was written in the letter, “And I know their count, seventy men, and they are with the elders of the city who are raising them.²Alternatively, “now the kings sons, etc.” until the end of the verse was not written in the letter. Rather, it is a comment by [Yirmiyahu] the author of the Book of Kings.—Radak