John Calvin Commentary Psalms 69:31

"And it will please Jehovah better than an ox, [Or] a bullock that hath horns and hoofs." — Psalms 69:31 (ASV)

And this will please Jehovah more than a young bullock. To more effectively strengthen himself for this act of worship, David affirms that the thanksgiving he is about to offer will be to God a sacrifice of a sweet and acceptable aroma. There can be no more powerful motivation for thanksgiving than the certain conviction that this religious service is highly pleasing to God, especially since the only repayment He requires for all the benefits He bestows on us is that we honor and praise His name.

This highlights even more clearly the inexcusability of those who are so slow that, by their silence or forgetfulness, they suppress the praises of God. David neither omitted nor despised the outward sacrifices which the law commanded; but he very rightly preferred the spiritual service, which was the ultimate purpose of all the Levitical ceremonies.

I have discussed this subject more fully in my comments on Psalm 50:14. It is also worth noting David's humility: although he rose so high as to be a heavenly example, he did not disdain to humble himself for the general benefit of the Church, as if he belonged to the ordinary people. He did this so that, through the symbols of the law, he might learn the truth that has since been more clearly revealed in the gospel—namely, that the praises of God, insofar as they come from our mouths, are impure until they are sanctified by Christ.

But how blatant and foolish is the superstition of those who would reintroduce the outward display of ceremonies abolished by the one sacrifice of Christ’s death! They think God is truly appeased when they have tired themselves out with useless activities.

What does this achieve, other than to obscure or cover, through the use of thick veils, this true service of thanksgiving, which David did not hesitate to greatly prefer to the Mosaic ceremonies, even though these were divinely appointed?

By a young bullock, he means one of the choicest, and the point he intends to make is that there was no sacrifice or victim, however valuable or precious, that he could offer in which God would take such great delight as in thanksgiving.