Psalms 50:5

O ye angels, summon and fetch them to my tribunal; which is poetically spoken; not as if they were actually to do so, but only to continue the metaphor and representation of the judgment here mentioned. My saints; the delinquents, the Israelites, whom he calls saints; partly, because they were all by profession a holy people, as they are called, Deuteronomy 14:2; partly, by an irony, intimating how unworthy they were of that name; and partly, as an argument or evidence against them, because God had chosen and separated them from all the nations of the earth, to be a holy and peculiar people to himself, and they also had solemnly and frequently consecrated and devoted themselves to God, and to his faithful service; all which did greatly aggravate their present apostacy. Those that have made a covenant with me by sacrifice, i.e. which have entered into covenant with me, and have ratified that covenant with me by sacrifice, not only in their parents, Exodus 24:4, &c., but also in their own persons from time to time, even as oft as they offer sacrifices to me. This clause seems to be added here, to acquaint them with the proper nature, use, and end of sacrifices, which were principally appointed to be signs and seals of the covenant made between God and his people; and consequently to convince them of their great mistake and wickedness in trusting to their outward sacrifices, when they neglect the very life and soul of them, which was the keeping of their covenant with God; and withal to diminish that overweaning conceit which they had of sacrifices, and to prepare the way for the abolition of them, as being only necessary to confirm the covenant; which being once for all confirmed by the blood of Christ, they might without any inconvenience be laid aside and abrogated.