Adam Clarke on Psalms 54:6

I will freely sacrifice unto thee - Or, I will sacrifice nobly unto thee. Not only with a willing mind, but with a liberal hand will I bring sacrifice unto thee.

For it is good - Thy name is good; it is descriptive of thy nature; full of goodness and mercy to man. And it is good to be employed in such a work: whoever worships thee in sincerity is sure to be a gainer. To him who orders his conversation aright, thou dost show thy salvation.