Genesis 4:6

“And the Lord said unto Cain, why art thou wroth? and why is thy countenance fallen? etc.] Which was said not as being ignorant of his wrath and resentment, but to bring him to a conviction of his sin or sins, which were the cause of God’s rejecting his sacrifice, and to repentance and amendment; and to show him that he had no cause to be displeased, either with him or his brother, for the different treatment of him and his offering; since the fault lay in himself, and he had none to blame but his own conduct, which for the future he should take care to regulate according to the divine will, and things would take a different turn.”

“- Section IV - The Family of Adam - Cain and Abel 1. קין qayı̂n, Qain (Cain), “spear-shaft,” and קנה qānah, “set up, establish, gain, buy,” contain the biliteral root קן qan, “set up, erect, gain.” The relations of root words are not confined to the narrow rules of our common etymology, but really extend to such instinctive usages as the unlettered speaker will invent or employ. A full examination of the Hebrew tongue leads to the conclusion that a biliteral root lies at the base of many of those triliterals that consist of two firm consonants and a third weaker one varying in itself and its position. Thus, יטב yāṭab and טיב ṭôb. So קין qayı̂n and קנה qānah grow from one root. 2. הבל…”

“Ch1 13:11-13; Job 5:2; Isa 1:18; Jer 2:5, Jer 2:31; Joh 4:1-4, Joh 4:8-11; Mic 6:3-5; Mat 20:15; Luk 15:31, Luk 15:32 Genesis 4:7”