Where did Cain get his wife

Where did Cain get his wife

In the rules of Rabbi Eliezer:

E1. Ribbuy (extension): The particles “et” את, “gam” גם, and “af” אף, which are superfluous indicate that something which is not explicitly stated must be regarded as included in the passage under consideration, or that some teaching is implied thereby.

See את in Ge 1:1 and this Col 1:16 For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether [they be] thrones, or dominions, or principalities, or powers: all things were created by him, and for him:

Eph 1:10 That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; [even] in him:

This rule is used by Rashi to derive from the Hebrew that Cain had a twin sister and Abel has two twin sisters (triplets). Genesis Rabbah 22:2.

So there is manuscript evidence that there were more than just Cain and Abel.

והאדם ידע את חוה אשתו ותהר ותלד את קין ותאמר קניתי איש את יהוה Ge 4:1

ותסף ללדת את אחיו את הבל ויהי הבל רעה צאן וקין היה עבד אדמה Ge 4:2