Midrasch zu Jechezkiel 16:5

Rabbi Shela said: All the children (of the Israelites) whom the Egyptians cast into the river did not die, for the river cast them up, and threw them into the desert of Egypt. The Holy One, blessed be He, brought a rock to the mouth of each one, and a rock to the side of each one. The rock which was at his mouth was feeding him with honey and milk, and the rock which was at their side was anointing them with oil, like a lying-in woman who anoints her son, as it is said, "And he made him to suck honey out of the rock, and oil out of the flinty rock" (Deut. 32:13). When Israel came to the sea, they saw the Holy One, blessed be He, and they recognized Him, and praised Him, and sanctified Him, as it is said, "This is my God, and I will praise him" (Ex. 15:2).