Exode 2:3

But she could conceal him no longer, for the Mizraee had become aware of him. And she took an ark of papyrus, (tunes,) and coated it with bitumen and pitch, and placed the child within it, and laid him among the reeds on the bank of the river.

The thoughts of God are deep; who can perceive His secret? To Him alone the plot is clear. Perhaps God caused it to come about that Moshe would grow up in the royal palace, that his soul might be habituated to be on the highest level, not lowly and accustomed to being in a house of slaves. For do we not see that he kills the Egyptian for performing an act of unjust violence? And he saves the Midianite daughters from the shepherds, for they (the shepherds) perform unjust violence in watering their flocks from the water drawn by them (the daughters of Re’uel). And moreover: had he grown up among his brethren, such that they had known him since his youth, they would not be in awe of him, for they would consider him as one of them.

בחמר, on the inside,

ובזפת, on the outside, so that the water would not get inside the basket.

ותשם בסוף; which was על שפת היאור, near the embankment of the river. People walking along the river would not automatically be able to spot the basket from the outside, but people bathing in the river would be able to see it. Yocheved had not entered the water to hide the basket from all directions. This is why the daughter of Pharaoh saw the basket while she was bathing in the river. Her maidservants, who were only walking along the embankment, had not noticed the basket and who was inside it.

ותשם בסוף, a place where the people passing would not see her deposit the basket; in spite of this, the reason why she chose the reeds was that she thought the decree of babies having to be thrown into the river had been fulfilled by placing him within the river’s domain.

ולא יכלה עוד הצפינו, “she could not (successfully) hide him any longer; Rashi comments here that the Egyptians had kept track of when Yocheved had finished serving as the King’s midwife, and calculated the earliest date that she could give birth to a child from her husband. At the end of nine months they checked her out. They had allowed for the fact that she might have been three months pregnant when appointed as midwife. This explains why she felt safe hiding her baby during the first three months.

תיבת גומא, “an ark of bulrushes;” seeing that the basket resembles in texture and colour the bulrushes along the river Nile, it was suitably camouflaged. The Talmud tractate Sotah, folio 12, uses this example as proof that the righteous consider their belongings as even more important than their bodies. [She used inexpensive material, as the chances that both Moses and the basket would be lost to her were overwhelming. Ed.] This is not a reflection on the righteous being tightfisted with their money, but a result of their being careful not to acquire any possessions illegally.

ותחמרה בחמר, “she daubed it with slime (and pitch)”. She put the former on the outside and the latter on the inside; in order that it would not attract attention of passers by. Even though the pitch was evil smelling, if she had put it on the outside, being black it would have attracted too much attention. However, Rashi¸ makes the opposite point; he says that the זפת she applied on the outside so that Moses would not have to inhale its unpleasant odour, whereas the slime was on the inside. Ibn Ezra considers the word חמר as referring to a type of bulrushes.