Jesus warns Peter that Satan has demanded to sift the disciples like wheat (Luke 22:31). The agricultural metaphor pictures grain tossed in a sieve to separate kernels from chaff—violent shaking that exposes what's real and what's worthless. Satan desires to prove the disciples' faith is merely chaff that will blow away under pressure. But Jesus prays for Peter specifically, that his faith will not fail. The verb's intensity matches the crisis ahead: Judas's betrayal, Jesus's arrest, Peter's denials. Yet sifting, though violent, serves a purpose—refining genuine faith.