ARK OF MOSES("tebah"):
For three months Moses was kept hidden by his mother, and when she could no longer conceal him, she made a box and launched it on the Nile river (Ex. ii. 2-3). The box was made of rushes, and was lined with slime and pitch to make it water-tight. Midr. R. to Ex. i. 21 says that the pitch was placed on the outside of the box, so that its odor should not be offensive to the infant.