I will freely sacrifice unto thee,.... Not legal sacrifices; no, nor freewill offerings the law gives directions about, though the allusion is to them; but the freewill offerings of his mouth, Psa 119:108; the sacrifices of praise and thanksgiving, on account of help, salvation, and deliverance, as appears from the following clause; which he determines to offer, not by constraint, but willingly; not by force, but of a ready mind; freely, and with all his heart. The sacrifice of his antitype is himself, his soul and body, as in union with his divine Person; and this was offered up to God, against whom man has sinned, and whose justice must be satisfied; and this was done freely and voluntarily; he gave himself an offering; he laid down his life of himself, and that for sinners. The sacrifices of his people are their prayers and praises, their acts of beneficence, and the presentation of their souls and bodies in divine service; all which they do freely, under the influence of divine grace; I will praise thy name, O Lord; which explains what is meant by sacrificing: this is what is due to the Lord, and comely in his people; for it is good; either the name of God; and therefore to be praised. He himself is good, as, he is, both in a way of providence and of grace; and it is good, both pleasantly and profitably good, to sing praises to him, Psa 147:1.