Quran 7:135 — The Purgatory (Al-A'araf)

Yet, when we relieved the plague for any length of time, they violated their pledge.

[7:134] Whenever a plague afflicted them, they said, "O Moses, implore your Lord—you are close to Him. If you relieve this plague, we will believe with you, and will send the Children of Israel with you."

[7:136] Consequently, we avenged their actions, and drowned them in the sea. That is because they rejected our signs, and were totally heedless thereof.