Comentario sobre Génesis 4:1

(1) והאדם ידע AND THE MAN KNEW already before the events related above took place — before he sinned and was driven out of the Garden of Eden. So, also, the conception and birth of Cain took place before this. Had it been written, וידע אדם it would imply that after he was driven out children were born to him (Genesis Rabbah 22:2).

AND SHE CONCEIVED AND BORE CAIN. The sense of it is that she gave birth to a son, and she called his name Cain [from the word kanah, acquisition], because she said, I have gotten a man with [the help of] the Eternal. In a similar sense is the verse, And she conceived and bore Enoch,⁴¹⁵Further, Verse 17. and many similar verses in this chapter and in other places.
“Eth Hashem (with the Eternal). When He created me and my husband He created us by Himself, but in the case of this one, we are co-partners with him.” Thus the words of Rashi.
The correct interpretation appears to me to be that she said: “This son will be for me an acquisition for the Eternal, for when we shall die he will exist in our stead to worship his Creator.” This is also the opinion of Onkelos who translated eth hashem to mean “before the Eternal.” [The word eth in the following verses is translated] in a similar sense: And it shall be shown ‘eth hakohen’ (the priest),⁴¹⁶Leviticus 13:49. meaning to the priest; And David came near ‘eth ha’am’ (the people),⁴¹⁷I Samuel 30:21. meaning to the people. Or it may be that eth hashem has the same interpretation as in the verses: And Enoch walked ‘eth ha’elokim’ (with G-d);⁴¹⁸Genesis 5:22. See following note. Noah walked ‘eth ha’elokim’ (with G-d).⁴¹⁹Ibid., 6:9. The sense here in the verse before us would thus be: I have acquired a man to walk with G-d.
Now she [Eve] called one son by a name indicating “acquisition,” and the second one she called Abel, denoting “vanity” because man’s acquisition is likened to vanity. But she did not wish to say so explicitly. Therefore, no reason is written for the name of the second son. The secret received by tradition concerning Abel is very profound.⁴²⁰See my Hebrew commentary, p. 43.

ותלד את קין. She gave birth to Cain. According to our sages Cain represented the spirit of impurity and evil whereas Abel represented good. Abel's soul is supposed to have been reincarnated in the body of Moses (compare Zohar 1,54 on this passage). Abel suffered multiple injuries at the hands of Cain because Cain did not know where to inflict a lethal injury. The pains suffered by Abel in the process removed any vestige of evil that may have been in him so that when Moses was born he was totally good. This is what Eve hinted at when she said: קניתי איש את השם. She meant that the perfection of a man such as Moses who could commune freely with G'd, was due only to the sufferings undergone by his ancestor Abel.