'Old' in the Bible

Nicodemus saith unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?

As a result of this many of His disciples abandoned Him, and no longer walked with Him.

Then said the Jews unto him, Thou art not yet fifty years old, and hast thou seen Abraham?

But how it is he is now able to see, or who made his eyes open, we are not able to say: put the question to him; he is old enough to give an answer for himself.

That was the reason why they said, He is old enough; put the question to him.

Verily, verily, I say unto thee, When thou wast young, thou girdedst thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall gird thee, and carry thee whither thou wouldest not.