(50) Why did Noah build an altar without having been commanded to do so? (#Ge 8:20). The requital of gratitude which is due to God ought to be offered to him without command, and without any delay or hesitation, showing the mind to be free from vices; for it becomes that man, who has been endued with blessings by God, to offer him his thanks with a grateful and willing mind; but he who delays to do so, waiting for an express command, is ungrateful, being as it were compelled by necessity honour his benefactor.
(51) Why is he said to have built an altar to God, and not to the Lord? (#Ge 8:20). In passages of beneficence and regeneration, as at the creation of the world, the sacred writer only refers to the beneficent virtue of the Creator, by which he makes everything in its integrity, and he implies this by concealing the royal name of Lord, as one which bears with it supreme authority; therefore now also, since what he is describing is the beginning of the renewed generation of mankind, he borrows for his description the beneficent virtue, which bears the name of God; for he used the kingly attribute, which declares his imperial power, by which he is called Lord, when he was describing the punishment inflicted by the flood.
(52) What is the meaning of the statement, “He took of the cattle and of the flying animals, and he offered whole burnt offerings on the altar?” (#Ge 8:20). All this is said with reference to an inward meaning, both because he received everything from God as a favour and gift; and also because he took of the clean sorts of animals, and burnt those which were unpolluted and clean, as entire and pure first fruits; for they are proper victims for good men to offer, and are themselves entire, being full of integrity; and they may be classed as fruits, for fruit is the end, for the sake of which the plant exists. This indeed is the literal statement; but with respect to the inner meaning, the clean cattle and the clean birds are the outward senses and intellect of the wise man, with the thoughts which are received in his mind; all which things it is reasonable to offer in their integrity as entire and perfect fruit, in the way of a display of gratitude to the Father, and to offer them to him as an unpolluted and clean oblation of a victim.