Let thy gifts be to thyself— This is a compliment. He afterwards accepts what he here declines through civility. He means to say, that he was ready to do whatever the king commanded, without any respect to a recompense. See Calmet.
Related Commentaries of Daniel 5:17
Daniel 5:17
17 Then Daniel answered and said before the king, Let thy gifts be to thyself, and give thy rewardsi to another; yet I will read the writing unto the king, and make known to him the interpretation.