All the firstborn males that come of your herd and of your flock you shall sanctify unto the LORD your God: you shall do no work with the firstborn of your bullock, nor shear the firstborn of your sheep.
All Commentaries on Deuteronomy 15:19 Go To Deuteronomy 15
Paterius
AD 606
What did Moses mean by making this prohibition, except to forbid those who have begun to live aright to engage in human occupations? To plow with the firstborn of a cow is to display the beginnings of one’s conversion in carrying out public activities. To shear the firstborn of sheep is to strip the cover of secrecy from our first good works and display them to human eyes. Therefore we are forbidden to work with the firstlings of cattle. When we are kept from shearing the firstlings of the sheep, we should not act openly too quickly, even if we have begun some solid work. Since our life begins as something simple and innocuous, it is proper that we should not lay aside the covering of its privacy, lest it show itself naked to human eyes once the wool has been sheared. The firstlings of cattle and sheep are suitable only for divine sacrifices. Whatever we begin with that is strong, simple and innocent, we should offer on the altar of our hearts to the honor of the secret judge. And he without a doubt receives it more gladly if it has been hidden from men and not stained with any desire for praise. But often the beginnings of a new conversion are mixed with elements of a carnal life and hence should not become known too quickly. Otherwise, when the good that is acceptable is praised, the soul is deceived by praise and cannot grasp the evils that still lie concealed in it. Exposition of the Old and New Testament, Deuteronomy
