She took for him an ark of bulrushes. The words translated "ark" and "bulrushes" are both of Egyptian origin, the former corresponding to the ordinary word for "chest," which is feb, teba, or tebat, and the latter corresponding to the Egyptian kam, which is the same in Coptic, and designates the papyrus plant.
This is a strong-growing rush, with a triangular stem, which attains the height of from 10 to 15 feet. The Egyptian paper was made from its pith. The rush itself was used for various purposes — among others for boat-building (Plin.
'H. N.' 6:22; 7:16; Theophrast, 4:9; Pint. 'De Isid. et Osir.' § 18, etc.), as appears from the monuments. It would be a very good material for the sort of purpose to which Jochebed applied it. She daubed it with slime and with pitch.
The word translated "slime" is the same as that used in Genesis 11:3, which is generally thought to mean "mineral pitch" or "bitumen." According to Strabo and Dioderus, that material was largely used by the Egyptians for the embalming of corpses, and was imported into Egypt from Palestine.
Boats are sometimes covered with it externally at the present day; but Jochebed seems to have used vegetable pitch- the ordinary pitch of commerce — for the purpose. Here again the Hebrew word is taken from the Egyptian.
She laid it in the flags. "Suph," the word translated "flags," is a modification of the Egyptian tuff, which has that meaning. Water-plants of all kinds abound in the backwaters of the Nile. and the marshy tracts communicating with it.
The object of placing the ark in a thicket of reeds probably was, that it might not float away out of sight. The river's brink. Literally, the lip of the river — an Egyptian idiom.