Or HaChaim on Deuteronomy 10:17/אור החיים על דברים י׳:י״ז

1 אלוקי האלוקים ואדוני האדנים, "The G'd of gods and the Lord of lords, etc." The first statement means that He is the G'd of the angels who are often described as אלהים, such as in Job 1,6 ויבאו בני האלוהים. The expression אדני האדנים refers to terrestrial rulers. Compare Genesis 42,30 דבר האיש אדני הארק אתנו קשות, "the man who is the ruler of the land spoke harshly to us." The reason Moses also had to mention terrestrial rulers is so that we should not think that these rulers are free to do as they please; Moses reminds us that G'd exerts some pressure on those rulers. This is what Solomon meant in Proverbs 21,1: "the heart of the king is in G'd's hand, He directs it to whatever direction He desires."