▼ The introduction of the conditional clause with an interrogative particle prods the answer from Cain, as if he should have known this. It is not a condemnation, but an encouragement to do what is right.

▼ The Hebrew text is difficult, because only one word occurs, שְׂאֵת (s^e’et), which appears to be the infinitive construct from the verb “to lift up” (נָאָשׂ, na’as). The sentence reads: “If you do well, uplifting.” On the surface it seems to be the opposite of the fallen face. Everything will be changed if he does well. God will show him favor, he will not be angry, and his face will reflect that. But more may be intended since the second half of the verse forms the contrast: “If you do not do well, sin is crouching….” Not doing well leads to sinful attack; doing well leads to victory and God’s blessing.

▼ The Hebrew term translated “crouching” (רֹבֵץ, rovets) is an active participle. Sin is portrayed with animal imagery here as a beast crouching and ready to pounce (a figure of speech known as zoomorphism). An Akkadian cognate refers to a type of demon; in this case perhaps one could translate, “Sin is the demon at the door” (see E. A. Speiser, Genesis [AB], 29, 32–33).

▼ Heb “and toward you [is] its desire, but you must rule over it.” As in Gen 3:16, the Hebrew noun “desire” refers to an urge to control or dominate. Here the desire is that which sin has for Cain, a desire to control for the sake of evil, but Cain must have mastery over it. The imperfect is understood as having an obligatory sense. Another option is to understand it as expressing potential (“you can have [or “are capable of having”] mastery over it.”). It will be a struggle, but sin can be defeated by righteousness. In addition to this connection to Gen 3, other linguistic and thematic links between chaps. 3 and 4 are discussed by A. J. Hauser, “Linguistic and Thematic Links Between Genesis 4:1–6 and Genesis 2–3, ” JETS 23 (1980): 297-306.