Mark 14:39
He went away again and prayed, saying the same words.
Matthew 6:7
Matthew 26:42-44
He went away a second time and prayed, saying,
Luke 18:1
Now Jesus was telling the disciples a parable to make the point that at all times they ought to pray and not give up and lose heart,
2 Corinthians 12:8
Concerning this I pleaded with the Lord three times that it might leave me;