Was cast out - When he was exposed on the banks of the Nile, Exodus 2:3.
And nourished him - Adopted him, and treated him as her own son, Exodus 2:10. It is implied in this that he was educated by her. An adopted son in the family of Pharaoh would be favored with all the advantages which the land could furnish for an education.

And when he was cast out,.... Into the river, or by the river, as some copies read; the Syriac version adds, by his own people; by his father and mother and sister; who might be all concerned in it, and were privy to it; and which was done after this manner; his mother perceiving she could keep him no longer, made an ark of bulrushes, daubed with slime and pitch, into which she put him; and then laid it in the flags, by the river's side, and set his sister Miriam at a proper distance, to observe what would be done to him, Exodus 2:3.
Pharaoh's daughter took him up; her name, according to Josephus (w), was "Thermuthis"; she is commonly, by the Jews (x), called "Bithiah"; and by Artapanus in Eusebius (y), she is called "Merrhis". This princess coming down to the river to wash, as she and her maidens were walking by the river side, spied the ark in which the child was laid, among the flags, and ordered one of her maids to go and fetch it; and which being done by her orders, is attributed to her; and opening the ark, she was struck at once with the loveliness of the babe, and being filled with compassion to it, which wept, she took him,
and nourished him for her own son: not that she took him to the king's palace, and brought him up there, but the case was this; Miriam the sister of Moses, observing what was done, and perceiving the inclination of Pharaoh's daughter to take care of the child, offered to call an Hebrew nurse, to nurse the child for her; to which she agreed, and accordingly went and fetched her own and the child's mother, who took it upon wages, and nursed it for her; and when it was grown, brought it to her, who adopted it for her son, Exodus 2:5. According to Josephus (z), and some other Jewish writers (a), so it was, that when the child was taken out of the ark, the breast was offered it by several Egyptian women, one after another, and it refused to suck of either of them; and Miriam being present, as if she was only a bystander and common spectator, moved that an Hebrew woman might be sent for; which the princess approving of, she went and called her mother, whose breast the child very readily sucked; and at the request of the princess she took and nourished it for her: according to Philo the Jew (b), this princess was the king's only daughter, who had been a long time married, but had had no children, of which she was very desirous; and especially of a son, that might succeed in the kingdom, that so the crown might not pass into another family; and then relating how she came with her maidens to the river, and found the child; and how that the sister of it, by her orders, fetched an Hebrew nurse to her, which was the mother of the child, who agreed to nurse it for her; he suggests that from that time she gave out she was with child and feigned a big belly, that so the child might be thought to be ' "genuine, and not counterfeit": but according to Josephus (c), she adopted him for her son, having no legitimate offspring, and brought him to her father, and told him how she had taken him out of the river, and had nourished him; (Josephus uses the same word as here;) and that she counted of him to make him her son, and the successor of his kingdom; upon which Pharaoh took the child into his arms, and embraced him, and put his crown upon him; which Moses rolling off, cast to the ground, and trampled upon it with his feet: other Jewish writers say (d), that he took the crown from off the king's head, and put it on his own; upon which, the magicians that were present, and particularly Balaam, addressed the king, and put him in mind of a dream and prophecy concerning the kingdom being taken from him, and moved that the child might be put to death; upon which his daughter snatched it up, and saved it, the king not being forward to have it destroyed: and they also tell this story as a means of saving it, that Jethro who was sitting by, or Gabriel in the form of one of the king's princes, suggested that the action of the child was not to be regarded, since it had no knowledge of what it did; and as a proof of it, proposed that there might be brought in a dish, a coal of fire, and a piece of gold, or a precious stone; and that if he put out his hand and laid hold on the piece of gold, or precious stone, then it would appear that he had knowledge, and deserved death; but if he took the coal, it would be a plain case that he was ignorant, and should be free: the thing took with the king and his nobles, and trial was made, and as the child put out his hand to lay hold on the piece of gold or precious stone, the angel Gabriel pushed it away, and he took the coal, and put it to his lips, and to the end of his tongue; which was the cause of his being slow of speech, and of a slow tongue: by comparing Philo's account with this text, one would be tempted to think that Pharaoh's daughter did really give out, that Moses was her own son; and the author of the epistle to the Hebrews seems to confirm this, Hebrews 11:24 who says, "that Moses denied to be called, or that he was the son of Pharaoh's daughter"; as the words may be rendered.
(w) Antiqu. l. 2. c. 9. sect. 5, 7. & l0, 12. (x) Targum in 1 Chron. iv. 18. Shemot Rabba, sect. 1. fol. 91. 3. Vajikra Rabba, sect. 1. fol. 146. 3. & Pirke Eliezer, c. 48. T. Bab. Megilla, fol. 13. 1. & Derech Eretz Zuta, c. 1. fol. 19. 1. & Chronicon Mosis, fol. 4. l. (y) De prepar. Evangel l. 9. c. 27. (z) Antiqu. l. 2. c. 9. sect. 5. (a) Shemot Rabba, sect. 1. fol. 91. 3. Hebrews. Chronicon Mosis, fol. 4. 1. Jarchi in Exod. ii. 7. (b) De Vita Mosis, l. 1. p. 604, 605. (c) Antiqu. l. 2. c. 9. sect. 7. (d) Shemot Rabba, sect. 1. fol. 91. 3. Chronicoa Mosis, fol. 4. 2. Shalshalet Hakabala, fol. 5. 2.

Pharaoh's daughter took him up - By which means, being designed for a kingdom, he had all those advantages of education, which he could not have had, if he had not been exposed.