If he sleepeth, he will recover. [1] Replying that sleep will have a salutary effect on Lazarus, they thus endeavor indirectly to dissuade Christ from going thither. And yet they do not craftily or deceitfully turn aside Christ's words to suit their own purpose, on the pretense of not understanding what he said; [2] but, thinking that he spoke about sleep, they gladly seize this opportunity of avoiding danger. Augustine, and many writers since his time, speculate about the word sleep, alleging that the reason why it is applied to death is, because it is as easy for God to raise the dead to life, as it is for us to perform the customary act of awaking those who are asleep. But that nothing of this sort came into the mind of Christ, may be inferred from the constant use of the term in Scripture; and since even profane writers usually apply this word Sleep to Death, [3] there was unquestionably no other reason why it came into use, but because a lifeless corpse lies without feeling, just as the body of a man who is in a profound sleep. Hence, also, sleep is not inappropriately called the image of death, and Homer calls it the brother of death, (kasignetos thanatouu.) Since this word denotes only the sleep of the body, it is prodigiously absurd to apply it -- as some fanatics have done -- to souls, as if, by being deprived of understanding, they were subject to death. But I go to awake him. Christ asserts his own power, when he says that he will come to awake Lazarus; for, though, as we have said, the word sleep does not express the facility of the resurrection, yet Christ shows that he is Lord of death, when he says, that he awakes those whom he restores to life.

Footnotes

1 - "Il sera guairi."

2 - "Comme faisans semblant de n'entendre point ce que Christ dit."

3 - "Et mesmers veu que les autheurs profanes transferent coustumierement ce mot de Dormir a la Mort."

If the sleep, he shall do well - Sleep was regarded by the Jews, in sickness, as a favorable symptom; hence it was said among them, "Sleep in sickness is a sign of recovery, because it shows that the violence of the disease has abated" (Lightfoot). This seems to have been the meaning of the disciples. They intimated that if he had this symptom, there was no need of his going into Judea to restore him.

If he sleep, he shall do well - That is, if he sleep only, etc. Though the word sleep frequently meant death, (see Acts 7:60; 1-Corinthians 11:30; 1-Corinthians 15:18, 1-Corinthians 15:20), yet, as it was an ambiguous term, the disciples appear here to have mistaken its meaning. Because, in certain acute disorders, the composing the patient to rest was a favorable sign; therefore the words, If he sleep, he shall do well, or recover, became a proverbial forth of speech among the Jews. In most diseases, sleep is a very favorable prognostic: hence that saying of Menander: -
Ὑπνος δε πασης εϚιν ὑγιεια νοσου.
Sleep is a remedy for every disease.
See Grotius here. The meaning of the disciples seems to have been this: There can be no need for thee to go into Judea to awake our friend Lazarus; he will awake time enough, and his very sleep is a presage of his recovery: therefore do not hazard thy life by going.

Then said his disciples, Lord, if he sleep,.... Soundly, quietly, and comfortably, and takes rest in it:
he shall do well; or "be saved" from the disease; he will be delivered from it; he will recover out of it; it is a sign the distemper is leaving him, and he is growing better, and will be restored to his health again: the Ethiopic version renders it by many words, "he will be well", and "will awake", and "will live". Sound sleep is a sign of health. This they said to, put off their master from going into Judea, fearing the danger he would be exposed unto.

if he sleep, he shall do well--literally, "be preserved"; that is, recover. "Why then go to Judea?"