kaj (kelubh; phulake): The earliest known form of cage made to confine a bird, for the pleasure of its song or the beauty of its coloring, was a crude affair of willows or other pliable twigs. Later cages were made of pottery, and now they are mostly made of wire. References in the Bible make it very clear that people were accustomed to confine in cages such birds as they especially prized for pets, or to detain them for market purposes. James indicated that cages were common when he wrote (3:7): "For every kind of beasts and birds .... is tamed, and hath been tamed by mankind." In Job (41:5) we find these lines
"Wilt thou play with him as with a bird?
Or wilt thou bind him for thy maidens?"
The only way to play with a bird is to confine it so that it grows accustomed to you and thus loses fear. Jeremiah compared the civil state of Judah to a "cage (crate) full of birds" (5:27), "the houses of the rich being stuffed with craftily-obtained wealth and articles of luxury" (HDB). The sale of sparrows as an article of food still continues in the eastern markets. Jesus referred to this (Mt 10:29) and it was He who entered the temple and overthrew "the seats of them that sold the doves" (Mt 21:12). In Re 18:2 we find a reference to "a hold (the King James Version "cage") of every unclean and hateful bird." See also Ec 11:10.