Genesis 4:2

And she again bare his brother Abel - Literally, She added to bear (ותסף ללדת vattoseph laledeth) his brother. From the very face of this account it appears evident that Cain and Abel were twins. In most cases where a subject of this kind is introduced in the Holy Scriptures, and the successive births of children of the same parents are noted, the acts of conceiving and bringing forth are mentioned in reference to each child; here it is not said that she conceived and brought forth Abel, but simply she added to bring forth Abel his brother; that is, as I understand it, Cain was the first-born, Abel, his twin brother, came next.

Abel was a keeper of sheep - Adam was originally a gardener, Abel a shepherd, and Cain an agriculturist or farmer. These were the three primitive employments, and, I may add, the most rational, and consequently the best calculated to prevent strife and an immoderate love of the world.

His brother Habel. - Habel means "breath, vanity." Does a sense of the vanity of earthly things grow in the minds of our first parents? Has the mother found her sorrow multiplied? Has she had many daughters between these sons? Is there something delicate and fragile in the appearance of Habel? Has Cain disappointed a mother's hopes? Some of all these thoughts may have prompted the name. There is something remarkable in the phrase "his brother Habel." It evidently points with touching simplicity to the coming outrage that was to destroy the peace and purity of the first home.

The two primitive employments of men were the agricultural and the pastoral. Here is the second allusion to some use which was made of animals soon after the fall. Coats of skin were provided for the first pair; and now we have Habel keeping sheep. In the garden of Eden, where the tree of life was accessible, an exclusively vegetable diet was designed for man. Whether this continued after the fall, we are not informed. It is certain that man had dominion over the whole animal kingdom. It can scarcely be doubted that the outer coverings of animals were used for clothing. Animals are presently to be employed for sacrifice. It is not beyond the bounds of probability that animal food may have been used before the flood, as a partial compensation for the desire of the tree of life, which may have been suited to supply all the defects of vegetable and even animal fare in sustaining the human frame in its primeval vigor.

Man in his primitive state, then, was not a mere gatherer of acorns, a hunter, or a nomad. He began with horticulture, the highest form of rural life. After the fall he descended to the culture of the field and the tending of cattle; but still he had a home, and a settled mode of living. It is only by a third step that he degenerates to the wandering and barbarous state of existence. And only by the predominance of might over right, the selfish lust of power, and the clever combinations of rampant ambition, comes that form of society in which the highest state of barbaric civilization and the lowest depth of bondage and misery meet.

4:2 Abel signifies vanity. The name given to this son is put upon the whole race, Psa 39:5. Every man is at his best estate vanity; Abel, vanity. He chose that employment which did most befriend contemplation and devotion, for that hath been looked upon as the advantage of a pastoral life. Moses and David kept sheep, and in their solitudes conversed with God.