Daniel 10:13

10:13 However, the prince of the kingdom of Persia was opposing me for twenty-one days. But Michael, one of the leading princes, came to help me, because I was left there with the kings of Persia.

Daniel 10:21

10:21 However, I will first tell you what is written in a dependable book. (There is no one who strengthens me against these princes, except Michael your prince.