‘And they were all astonished at the majesty of God.'
As the crowds saw what had happened they were filled with astonishment at the wonder of what it revealed God to be. In 2 Peter 1:16 the same word translated ‘majesty' is applied to Jesus at the Transfiguration. It was also applied by idolaters to their goddess Artemis (Acts 19:27). It thus depicts glory and splendour and divinity. Luke undoubtedly intends us to connect its use here with Jesus as revealed on the mountain, while strictly applying it to God, because the crowds had not been on the mountain. Both can be seen as One in majesty.
Superficially it is tempting to see here a case of epilepsy, but it will not pass muster. Had it been epilepsy we can be sure that the disciples would have been able to heal it, and that Jesus would not have seen it as a special case needing a deeper level of spirituality. In fact Jesus makes clear that it was a particularly difficult kind of evil spirit to deal with. But it had no option but to obey Him. His act revealed the majesty of Jesus.
It Is Urgent That His Disciples Become Aware That He Will Be Delivered Up Into The Hands Of Men (Luke 9:43).
This is the second warning that Jesus has given to them about what will happen to Him. He does not want them caught by surprise. He wants them to take His warning seriously.
Analysis.
a While all were marvelling at all the things which He did, He said to His disciples (Luke 9:43 b).
b “Let these words sink into your ears, for the Son of man shall be delivered up into the hands of men” (Luke 9:44).
a But they understood not this saying, and it was concealed from them, that they should not perceive it, and they were afraid to ask Him about this saying (Luke 9:45).
Note that in ‘a' the crowds were marvelling at what He did, and in the parallel the disciples are afraid to ask Him about what He has said. In ‘b' is the central point that they must allow the fact of His coming suffering at the hands of men ‘sink into their ears'. That is they must sit up and take very careful notice!
‘But while all were marvelling at all the things which he did, he said to his disciples,'
Having come down from the mountain where He has spoken with Moses and Elijah about His coming ‘exodus' He wants His disciples to become more aware of it than they are. But instead all the crowds are marvelling at what He has done, and that no doubt included the disciples (‘all'). So He once again takes His disciples on one side and speaks seriously with them.