Mark 9:38
And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us.
Cross-reference
Mark 10:13 repeats the disciples’ pattern of hindering others from coming to Jesus—first an exorcist, then children—both met with rebuke.
Numbers 11:26-29 shows Moses rebuking Joshua's jealousy over unauthorized prophets—a type of Jesus' response to John's exclusivity.
Luke 9:49 records the same incident—John reporting the unauthorized exorcist—providing the synoptic parallel to Mark's account.
Luke 9:50 records Jesus' reply—'he who is not against us is for us'—the same teaching as in Mark.
Numbers 11:28 has Joshua forbidding unauthorized prophets, mirroring John’s action. Moses’ reply prefigures Jesus’ rebuke: let all who serve God do so.
Acts 19:13 shows failed exorcists using Jesus’ name without faith, contrasting the genuine but unauthorized exorcist in Mark who succeeded.
Philippians 1:18 expresses Paul’s joy that Christ is preached even with wrong motives—echoing Jesus’ acceptance of genuine acts in His name.