What does Mark 9:42 mean?
"Sin" is from the Greek root word skandalizo which can mean to sin, but also means to draw someone away from whom they followed. "Little ones" is often interpreted as referring to the child Jesus presented in Mark 9:36–37. The Greek root word is mikros, which can mean someone younger but can also mean someone of lower rank and a lesser experience, like the unfamiliar man who cast out demons (Mark 9:38). When the disciples told that man to stop, they were telling him to sin."Millstone" is from the Greek root word mulos, and "great" is from the Greek root word onikos. While a mulos is just a millstone, onikos refers to something used with a donkey. Excavations from the area show that the mill used in Jesus' time wasn't just two wide cylinders on top of one another. The base stone was a heavy disk, the diameter perhaps twice its height, set on the ground with a circular track cut out of the flat top, leaving a raised lip and center. From the center rose a wooden post that pierced a heavy crossbeam. One end of the crossbeam acted as an axle for a smaller stone wheel that stood upright inside the larger cylinder's track. The other end of the post was harnessed to a donkey which walked around the base stone. As the smaller cylinder rolled around the post, it crushed grain in the carved track of the base stone.
This type of mill was particularly large, and the smaller stone wheel could be three feet in diameter and eighteen inches thick, making it more than enough to drown someone. The method of death is not fantasy, either. When the governor Quirinus commissioned the registration of the Jews and Joseph took the pregnant Mary to Bethlehem, Judas the Galilean led a revolt that resulted in some of his lieutenants being executed in exactly this manner (Acts 5:37). Still, Jesus says that drowning with a millstone around one's neck would be better than going to hell.
We're used to thinking of temptation as an enticement to do something wrong. At its core, however, all temptation is an attempt to draw someone away from God. Jesus explains this could be by keeping them from serving (Mark 9:38) or discouraging them from approaching Jesus (Mark 10:13–16). We need to seriously consider our church culture and whether we have established rules that keep others from fulfilling their God-given responsibilities of serving Him or learning more about Him.
Mark 9:42–48 shows that even if we follow the letter of the law, or maim ourselves in the attempt, we cannot be good enough to get to heaven on our own. In Matthew, directly after Jesus' hard words against sinning and tempting others to sin, Jesus talks about God's forgiveness and love for us (Matthew 18:12–14) and our responsibility to forgive others (Matthew 18:15–35). The various parallels in Matthew and Luke, as well as phrasing intended to transition subjects along suggest this passage is a synopsis of several different teachings. Still, Matthew 18:7–9 gives a reasonable parallel.
Mark chapter 9 contains an account of Jesus' transfiguration, where three of the disciples witness Him in a glorified form. In this passage, Jesus also heals a demon-possessed boy. His teachings in this section include a prediction of His death and resurrection, and corrections to the disciples' errors on questions of pride and temptation.