The Sifting Of Peter; Luke 22:31, 32.

Church History: Jesus, foreseeing the danger of Peter, and knowing that he was about to deny him, took the opportunity to forewarn him and put him on his guard, and also to furnish him with a solace when he should be brought to repentance. Satan hath desired. Satan is the prince of evil. One of his works is to try the faith of believers--to place temptations and trials in their way, which they may be tested. So Satan desired to have Peter in his hands, that he might also try him. May sift you as wheat. Grain was agitated or shaken in a kind of fan or sieve. The grain remained in the fan, and the chaff and dust were thrown off. So Christ says that Satan desired to try Peter; to place trials and temptations before him; to agitate him; to see whether anything of faith would remain, or whether all would not be found to be chaff--mere natural ardor and false professions.2
But I made supplication for thee, that thy faith fail not. Jesus, having insight into what was going on in the spirit world, made supplication that Peter might be enabled to endure the trial.
And do thou, when once thou hast turned again, establish thy brethren. The language sadly intimates that Satan's test would leave him in need of repentance. As the one who perhaps exercised the strongest influence over the other ten apostles, Peter is exhorted to use his own bitter experience for their benefit and strengthening.