Quran 2:249 — The Heifer (Al-Baqarah)

When Saul took command of the troops, he said, "GOD is putting you to the test by means of a stream. Anyone who drinks from it does not belong with me—only those who do not taste it belong with me—unless it is just a single sip." They drank from it, except a few of them. When he crossed it with those who believed, they said, "Now we lack the strength to face Goliath and his troops." Those who were conscious of meeting GOD said, "Many a small army defeated a large army by GOD's leave. GOD is with those who steadfastly persevere."

[2:248] Their prophet said to them, "The sign of his kingship is that the Ark of the Covenant will be restored to you, bringing assurances from your Lord, and relics left by the people of Moses and the people of Aaron. It will be carried by the angels. This should be a convincing sign for you, if you are really believers."

[2:250] When they faced Goliath and his troops, they prayed, "Our Lord, grant us steadfastness, strengthen our foothold, and support us against the disbelieving people."