“If you do well, will you not be accepted? And if you do not do well, sin is crouching at the door. Its desire is contrary to you, but you must rule over it.” (Genesis 4:7 ESV)
Most modern Bible versions render the verse as if sin in this verse is allegorized as a lion or some other predator. The Hebrew word has been translated “lie” or “couch”, rather than “crouch”, with domestic animals. But the context of Cain, sin and the desire image sounds much more like a predator, more like a wolf than a sheep.
The idea of a lion in cover comes again in verses like the wicked man of Psalm 10 : “like a lion in cover he lies in wait. He lies in wait to catch the helpless; he catches the helpless and drags them off in his net.” (Psalm 10:9, NIV)
The serpent again?
Many have asked could it be the same animal as Genesis 3, the serpent again? And some scholars consider that possible. For example one recent academic paper reviewing the question says “As to the identity of the ”coucher” in Gen 4:7, it is, of course, impossible to prove that it is the serpent of chapter 3. But the possibility should not be ruled out.” ” (Robert P. Gordon – essay: “Couch” or ”Crouch”? Genesis 4:7 and the Temptation of Cain, in On Stone and Scroll, 2011)
Yes, it would certainly have a nice consistency with Genesis 3 if sin is being presented as snake in the grass waiting to bite Cain. But the language seems to be a development from Genesis 3 and a different kind of animal.
The desiring animal
A stranger part of Genesis 4:7 than identifying the actual animal is that this animal should “desire” Cain. The Hebrew word tĕshuwqah here is only used with Eve in Genesis 3:16, Cain’s animal and Solomon’s beloved in Song 7:10.
Perhaps we should not over-think it. Temptation and the seed of temptation (death) are represented as a serpent and son of the serpent in Genesis 3:15, but then as a grandmother (desire), son (sin) and grandson (death).
“Then, after desire has conceived, it gives birth to sin; and sin, when it is full–grown, gives birth to death.” (James 1:15)
This then is more relevant to the New Testament and the Christian – presenting sin as a human personification, rather than an animalification.