A major shift was about to happen--His Spirit was about to be poured out on a believing Gentile named Cornelius, and Peter was the means through which it would happen. The problem was that for a Law-abiding Jewish believer like Peter, it was forbidden to go eat with a Gentile. (Acts 10:28)
To get the point across to Peter that believing Gentiles were not to be considered "unclean" if God had cleansed them through faith in Jesus, THREE TIMES God sends a vision of unclean animals that descend in a sheet, and Peter is commanded: "Arise, kill and eat!" Interestingly, in the vision, Peter knows who the command is coming from. He replies, "By no means, Lord..." Just then the Gentile men knock on his door and ask him to come to their Gentile master's house. Peter finally understands the meaning of the message....and realizes that he must obey God even when it goes against his natural inclination and upbringing.
This wasn't the first time Peter had rebuked the Lord. Just after proclaiming in confidence that Jesus was the Messiah, the Son of the Living God, Jesus tells His disciples that He will be beaten and crucified and rise again. Peter proclaims loudly: "God forbid it, Lord! This shall never happen to you!"
Peter had an idea what the Messiah plan should look like--and it didn't include crucifixion. He had no idea that God's plan was for salvation for Jews and Gentiles, and that it could only happen through Jesus' death on the cross.
There it is again...it wasn't until the third time that Peter realized how fully he had failed his Lord.
After the resurrection when Jesus met with Peter in Galilee, He asked him THREE TIMES: "Simon, son of John, do you love Me?" And THREE TIMES He told him what his new job was going to be..."Tend my lambs. Shepherd my sheep. Tend my sheep."
So...what is the significance of the THREE TIMES?
Peter didn't have any idea of his own weakness nor of the bigger plan of God. Again and again he was rebuking THE LORD JESUS and telling Him how things should go. And over and over it took Peter three times before the Message sunk in to him.
How many times does God send a Scripture, a truth, or an exhortation from a believer to speak something that we are just not comprehending because His ways are not our ways and His thoughts are not our thoughts?
Patiently He repeats what we are to do until we realize that God is working out His bigger picture according to His wisdom in ways we cannot comprehend.