No he knew what was going to happen they raised sheep so he knew that if you hit something enough it will die or at least no longer be living. I think he did it in a fit of rage and didn't know how to stop himself because that type of anger was a new thing to him. I think the only person that ever felt that kind of anger before Cain was God and that was before Cain was even born.
I always felt bad for Cain. And that’s why I got kicked out of bible study. See Cain was in charge of the grains, and Abel was in charge of the sheep. God comes down and asks for a sacrifice. Cain gives up grain, cause that’s what he had. God was having none of that. Cause you see, Abel had sheep and was able to give better sacrifices. In my understanding of the text, Cain knew exactly what he was doing even though he may have regretted it later. But God asked for blood, and Cain gave him what he asked for.
Plus “am I my brother’s keeper” is grade A sass and I love it.
The Bible does say Cain knew what he was doing, he would hold the better stuff for himself and not give the best to God. It didn’t matter that he had a “worse” sacrifice than his brother, his heart was not pure and his brothers was.
Plus “am I my brother’s keeper” is grade A sass and I love it.