'Sky' in the Bible

Look at the birds in the sky: They do not sow, or reap, or gather into barns, yet your heavenly Father feeds them. Aren't you more valuable than they are?

Jesus said to him, "Foxes have dens, and the birds in the sky have nests, but the Son of Man has no place to lay his head."

He said, "When evening comes you say, 'It will be fair weather, because the sky is red,'

and in the morning, 'It will be stormy today, because the sky is red and darkening.' You know how to judge correctly the appearance of the sky, but you cannot evaluate the signs of the times.