When Jesus heard that, he said,
This sickness is not unto death, but for the glory of God, that the Son of God might be glorified thereby.
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Cyril of Alexandria
AD 444
The Lord now says this, not that the men may go away and report it to the sisters of Lazarus, but as God foretelling what should come to pass, because He saw that the conclusion of the affair would be for the glory of God; not that the sickness came upon the man for this reason, that He should be glorified; for it would be silly to say this; but since it had come, He also saw that it would result in a wonderful end. And He says that Himself is in His Nature God, for that which is done, is done for His glory. For after saying that the sickness was for the glory of God, He added: That the Son of God may be glorified thereby, speaking concerning Himself.
And if He Himself said that the sickness of Lazarus was not unto death, and yet his death took place, there is nothing to marvel at. For looking on to the final result of the affair, and seeing that He was going to raise him up after a little time, we do not consider anything that took place in the interval, but only how the end would result. For the Lord determined to set forth the weakness of death, and to shew forth all that happened as for the glory of God, that is, of Himself.