MATTHEW 14 23 And when He had sent the multitudes away, He went up on the mountain by Himself to pray. Now when evening came, He was alone there. 24 But the boat was now in the middle of the sea, tossed by the waves, for the wind was contrary.25 Now in the fourth watch of the night Jesus went to them, walking on the sea. 26 And when the disciples saw Him walking on the sea, they were troubled, saying, “It is a ghost!” And they cried out for fear.27 But immediately Jesus spoke to them, saying, “Be of good cheer! It is I; do not be afraid.”28 And Peter answered Him and said, “Lord, if it is You, command me to come to You on the water.”29 So He said, “Come.” And when Peter had come down out of the boat, he walked on the water to go to Jesus. 30 But when he saw that the wind was boisterous, he was afraid; and beginning to sink he cried out, saying, “Lord, save me!”31 And immediately Jesus stretched out His hand and caught him, and said to him, “O you of little faith, why did you doubt?” 32 And when they got into the boat, the wind ceased.33 Then those who were in the boat came and worshiped Him, saying, “Truly You are the Son of God.” When they had crossed over, they came to the land of Gennesaret.

That He withdraws to pray alone, you should refer not to Him who fed five thousand on five loaves, but to Him who on hearing of the death of John withdrew into the desert; not that we would separate the Lord’s person into two parts, but that His actions are divided between the God and the man. (St. Jerome)