From the Gospel according to Mark
MK 3:13-19

Jesus went up the mountain and summoned those whom he wanted and they came to him. He appointed Twelve, whom he also named Apostles, that they might be with him and he might send them forth to preach and to have authority to drive out demons: He appointed the Twelve: Simon, whom he named Peter; James, son of Zebedee, and John the brother of James, whom he named Boanerges, that is, sons of thunder; Andrew, Philip, Bartholomew, Matthew, Thomas, James the son of Alphaeus; Thaddeus, Simon the Cananean, and Judas Iscariot who betrayed him.

From the Gospel according to Mark
MK 3:7-12

Jesus withdrew toward the sea with his disciples. A large number of people followed from Galilee and from Judea. Hearing what he was doing, a large number of people came to him also from Jerusalem, from Idumea, from beyond the Jordan, and from the neighborhood of Tyre and Sidon.
He told his disciples to have a boat ready for him because of the crowd, so that they would not crush him. He had cured many and, as a result, those who had diseases were pressing upon him to touch him. And whenever unclean spirits saw him they would fall down before him and shout, “You are the Son of God.”

From the Gospel according to Mark
MK 3:1-6

Jesus entered the synagogue. There was a man there who had a withered hand. They watched Jesus closely to see if he would cure him on the sabbath so that they might accuse him. He said to the man with the withered hand, “Come up here before us.” Then he said to the Pharisees, “Is it lawful to do good on the sabbath rather than to do evil, to save life rather than to destroy it?”
But they remained silent. Looking around at them with anger and grieved at their hardness of heart, Jesus said to the man, “Stretch out your hand.” He stretched it out and his hand was restored. The Pharisees went out and immediately took counsel with the Herodians against him to put him to death.

From the Gospel according to Mark
MK 2:23-28

As Jesus was passing through a field of grain on the sabbath, his disciples began to make a path while picking the heads of grain. At this the Pharisees said to him, “Look, why are they doing what is unlawful on the sabbath?” He said to them, “Have you never read what David did when he was in need and he and his companions were hungry? How he went into the house of God  when Abiathar was high priest and ate the bread of offering that only the priests could lawfully eat, and shared it with his companions?”  Then he said to them, “The sabbath was made for man, not man for the sabbath. That is why the Son of Man is lord even of the sabbath.”