'Air' in the Bible

A sower went out to sow his seed: and as he sowed, some fell by the way side; and it was trodden down, and the fowls of the air devoured it.

And Jesus said unto him, Foxes have holes, and birds of the air have nests; but the Son of man hath not where to lay his head.

It is like a grain of mustard seed, which a man took, and cast into his garden; and it grew, and waxed a great tree; and the fowls of the air lodged in the branches of it.