For thou desirest not sacrifice,.... Legal sacrifice; for there was no sacrifice appointed under the law for murder and adultery; else would I give it; he would gladly have offered it up; thou delightest not in burnt offering; at least such kind of sacrifices, though they were of divine appointment, and at that time in full force and use; yet they were not the only and principal sacrifices God desired and delighted in; nor were they at all acceptable to him without faith in Christ, and an humble sense of sin; and when offered in the best manner, yet spiritual obedience, acts of mercy, and sacrifices of praise and thanksgiving, were more pleasing to him, Sa1 15:15; wherefore the psalmist proposed to offer praise in Psa 51:15, and adds what follows.