Genesis 8:20

Noah builded an altar - As we have already seen that Adam, Cain, and Abel, offered sacrifices, there can be no doubt that they had altars on which they offered them; but this, builded by Noah, is certainly the first on record. It is worthy of remark that, as the old world began with sacrifice, so also did the new. Religion or the proper mode of worshipping the Divine Being, is the invention or institution of God himself; and sacrifice, in the act and design, is the essence of religion. Without sacrifice, actually offered or implied, there never was, there never can be, any religion. Even in the heavens, a lamb is represented before the throne of God as newly slain, Revelation 5:6, Revelation 5:12, Revelation 5:13. The design of sacrificing is two-fold: the slaying and burning of the victim point out, 1st, that the life of the sinner is forfeited to Divine justice; 2dly, that his soul deserves the fire of perdition.

The Jews have a tradition that the place where Noah built his altar was the same in which the altar stood which was built by Adam, and used by Cain and Abel, and the same spot on which Abraham afterwards offered up his son Isaac.

The word מזבח mizbach, which we render altar, signifies properly a place for sacrifice, as the root זבח zabach signifies simply to slay. Altar comes from the Latin altus, high or elevated, because places for sacrifice were generally either raised very high or built on the tops of hills and mountains; hence they are called high places in the Scriptures; but such were chiefly used for idolatrous purposes.

Burnt-offerings - See the meaning of every kind of offering and sacrifice largely explained on Leviticus 7:1-38.

The offering of Noah accepted. The return to the dry land, through the special mercy of God to Noah and his house, is celebrated by an offering of thanksgiving and faith. "Builded an altar." This is the first mention of the altar, or structure for the purpose of sacrifice. The Lord is now on high, having swept away the garden, and withdrawn his visible presence at the same time from the earth. The altar is therefore erected to point toward his dwelling-place on high. "Unto the Lord." The personal name of God is especially appropriate here, as he has proved himself a covenant keeper and a deliverer to Noah. "Of all clean cattle, and every clean fowl." The mention of clean birds renders it probable that these only were taken into the ark by seven pairs Genesis 7:3. Every fit animal is included in this sacrifice, as it is expressive of thanksgiving for a complete deliverance. We have also here the first mention of the burnt-offering עלה 'olâh; the whole victim, except the skin, being burned on the altar. Sacrifice is an act in which the transgressor slays an animal and offers it in whole, or in part as representative of the whole, to God. In this act he acknowledges his guilt, the claim of the offended law upon his life, and the mercy of the Lord in accepting a substitute to satisfy this claim for the returning penitent. He at the same time actually accepts the mercy of the Most High, and comes forward to plead it in the appointed way of reconciliation. The burnt-offering is the most perfect symbol of this substitution, and most befitting the present occasion, when life has been granted to the inmates of the ark amidst the universal death.

8:20 And Noah builded an altar - Hitherto he had done nothing without particular instructions and commands from God but altars and sacrifices being already of Divine institution, he did not stay for a particular command thus to express his thankfulness. And he offered on the altar, of every clean beast and of every clean fowl - One, the odd seventh that we read of, Genesis 7:2 ,3.