100:10

“And that which is in the breasts (of men) shall be made known?”

17:51

“Or some created thing that is yet greater (or harder) in your breasts (thoughts to be resurrected, even then you shall be resurrected).” Then they will say: “Who shall bring us back (to life)?” Say: “He Who created you first!” Then, they will shake their heads at you and say: “When will that be?” Say: “Perhaps it is near!”