Luke 6:12 (KJV) And it came to pass in those days, that he went out into a mountain to pray, and continued all night in prayer to God.

Luke reveals to us the prayer life of Jesus at least 6 times that are not in the other Gospels. He prayed here before he chose his twelve; he prayed at his baptism; he prayed after cleansing the leper; he prayed at his transfiguration; he prayed on the cross for those who crucified him; and finally he prayed in his dying breath. Luke just specialized in calling our attention to the prayer life of Jesus. All the Gospels do, but Luke went out of his way to give details that the others missed.

By this prayer Jesus made it clear that he was dependent upon the Father for guidance. He did not make this choice based on his own understanding, for he chose to limit his omniscience in matters like this. He was human using human understanding, and he may have been able to judge the best men for the job without help, but he chose to depend on the Father to lead him to the right men. He revealed his full humanity by this prayer of dependence. Had he been using his full deity within his humanity he would not need to pray at all, for he would know everything the Father knew, but this was not the case. Jesus emptied himself of the full deity he had in equality with the Father. He chose to leave with the limitations of his humanity, and this made him dependent upon the Father for wisdom and guidance.