Who could ever foresee, we used to stay up all night
At slumber parties, now I'm tryna rock this bitch to sleep
All the years we were real close, now I see his fears
Through her tears know she's wishing we were still close

from Jay-Z – D'Evils Lyrics on Rap Genius

The narrator never would have thought when they were little going to slumber parties that he would grow up and try to “rock this bitch to sleep” (kill one of his best friends).

But he is not completely cold hearted to the friend, he just feels the need to kill him is a business move. Since our narrator is suffering from the same issues as his friend he sympathizes with him, and would still like to be friends with him if they weren’t rivals.

It could be read differently. Jay-Z could be heard her to say “rock HIS bitch to sleep”, referring to his friends significant other.
The slumber parties was a reference to a more innocent time, a time when they were the “closest of friends”, but now he about to kill his former friend’s woman. She’s wishing they were still close because if they were she wouldn’t be about to die.

Yeah more alternate interpretation is Jay saying he tryna make her feel comfortable with the situation. Where im from rocking someone to sleep is tricking them into think that the situation is all good. Pulling the wool over their eyes. In this case I dont think that Jay meant he was gonna harm the girl but was tryna gain her trust only to go hurt his former friend.

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