Quran 2:73 — The Heifer (Al-Baqarah)

We said, "Strike (the victim) with part (of the heifer)." That is when GOD brought the victim back to life, and showed you His signs, that you may understand.

[2:72] You had killed a person, then disputed among yourselves. GOD was to expose what you tried to conceal.

[2:74] Despite this, your hearts hardened like rocks, or even harder. For there are rocks from which rivers gush out. Others crack and release gentle streams, and other rocks cringe out of reverence for GOD. GOD is never unaware of anything you do.