Psalm 99:6

Moses and Aaron among his priests, and Samuel among them that call upon his name; they called upon the LORD, and he answered them.

Moses and Aaron among his priests,.... The priests of the Lord, called and appointed by him, that ministered to him in that office, were the priests of Christ, types of him, and ceased when he came: these were the chief among them, or of them, as Kimchi observes: Moses officiated as a priest before Aaron was called and separated to that service; yea, it was he that consecrated and installed him in it, and that by offering sacrifice among other things, Exodus 29:1 Numbers 7:1, and that Aaron was the chief of them there can be no question, seeing he was the first from whom a race of priests sprung, and who gave name to that order of priesthood which continued until the Messiah's coming:

and Samuel among them that call upon his name; these, according to Kimchi, describe the prophets, among whom Samuel was the chief; see Acts 3:24 calling on the name of the Lord includes the whole worship of God, and is often used particularly of prayer; the object of which is God, and him only; and who is to be called upon at all times, and especially in a time of trouble, and always in faith, and with sincerity and truth; and an honour it is to be among such persons: now these three men, who were eminent for religion and piety, and particularly prayer, see Jeremiah 15:1 are mentioned to animate and encourage the saints, by their example, to the worship and service of the Lord, before exhorted to: they called upon the Lord; the Lord Christ, who is the object of invocation, was so in the Old Testament dispensation, and should be so in the New; see Acts 7:59. Moses called upon him, Exodus 32:11; so did Aaron, Numbers 16:22, and also Samuel, 1 Samuel 7:8,

and he answered them; as he does all his people, sooner or later, in one way or another; which is no small encouragement to pray unto him.