4:10 Mark alone noted that those who asked Jesus to explain the parables included the Twelve plus other disciples (v. 10). Evidently their question concerned why Jesus was using parables to teach as well as what they meant. He could have been clearer.
4:11-12 Jesus drew a distinction between those who accepted His teaching, such as the Twelve, and those who rejected it, such as the scribes and Pharisees. Those "outside"were those outside the circle of discipleship. God was giving those who welcomed Jesus' teaching new revelation about the coming messianic kingdom. He was withholding that revelation from those who rejected Him. The parables were the vehicle of that revelation. The Holy Spirit enabled the receptive to understand this enigmatic revelation, but He made it incomprehensible to the unbelieving. The parabolic method acted as a filter to separate those two types of people.
God was doing through Jesus what He had done through Isaiah centuries earlier. Jesus' quotation of Isaiah 6:9-10 drew this comparison. We might add that this is always the double effect of revelation (cf. 1 Cor. 2:6-16). God uses it to enlighten the receptive, but He also uses it to befuddle the unreceptive. Their inability to comprehend is a divine judgment for their unbelief (cf. Rom. 11:25-32). Further enlightenment requires positive reception of present revelation. This knowledge is very helpful for Jesus' disciples. It would have been an encouragement to Mark's original readers as they shared the gospel with others and noted the two responses.
"The judgment is a merciful one. The parable which the cold-hearted multitudes hear without understanding they remember, because of its penetrating and impressive form; and when their hearts become able to receive its meaning, the meaning will become clear to them. Meanwhile they are saved from the guilt of rejecting plain truth."107
