Matthew Henry on Deuteronomy 15:19-23

Here is a direction what to do with the firstlings. We are not now limited as the Israelites were; we make no difference between a first calf, or lamb, and the rest. Let us then look to the gospel meaning of this law, devoting ourselves and the first of our time and strength to God; and using all our comforts and enjoyments to his praise, and under the direction of his law, as we have them all by his gift.