30 Leaving there, they went through Galilee. He didn't want anyone to know their whereabouts, 31 for he wanted to teach his disciples. He told them, "The Son of Man is about to be betrayed to some people who want nothing to do with God. They will murder him. Three days after his murder, he will rise, alive." 32 They didn't know what he was talking about, but were afraid to ask him about it.
33 They came to Capernaum. When he was safe at home, he asked them, "What were you discussing on the road?" 34 The silence was deafening - they had been arguing with one another over who among them was greatest. 35 He sat down and summoned the Twelve. "So you want first place? Then take the last place. Be the servant of all." 36 He put a child in the middle of the room. Then, cradling the little one in his arms, he said, 37 "Whoever embraces one of these children as I do embraces me, and far more than me - God who sent me."
38 John spoke up, "Teacher, we saw a man using your name to expel demons and we stopped him because he wasn't in our group." 39 Jesus wasn't pleased. "Don't stop him. No one can use my name to do something good and powerful, and in the next breath cut me down. 40 If he's not an enemy, he's an ally.
Matthew Henry's Commentary on Mark 9:30-40
Commentary on Mark 9:30-40
(Read Mark 9:30-40)
The time of Christ's suffering drew nigh. Had he been delivered into the hands of devils, and they had done this, it had not been so strange; but that men should thus shamefully treat the Son of man, who came to redeem and save them, is wonderful. Still observe that when Christ spake of his death, he always spake of his resurrection, which took the reproach of it from himself, and should have taken the grief of it from his disciples. Many remain ignorant because they are ashamed to inquire. Alas! that while the Saviour teaches so plainly the things which belong to his love and grace, men are so blinded that they understand not his sayings. We shall be called to account about our discourses, and to account for our disputes, especially about being greater than others. Those who are most humble and self-denying, most resemble Christ, and shall be most tenderly owned by him. This Jesus taught them by a sign; whoever shall receive one like this child, receives me. Many have been like the disciples, ready to silence men who have success in preaching to sinners repentance in Christ's name, because they follow not with them. Our Lord blamed the apostles, reminding them that he who wrought miracles in his name would not be likely to hurt his cause. If sinners are brought to repent, to believe in the Saviour, and to live sober, righteous, and godly lives, we then see that the Lord works by the preacher.