And when they saw him, they worshipped him; but some doubted.
They worshiped Him with divine adoration as the eternal Son of God, declared so by His resurrection. Some had doubted before in Jerusalem, not believing the women or the disciples; now on the mountain, though they had seen Him many times and had all the proof they needed, some still questioned whether this was truly He or only a phantom, until He drew near and they knew Him.
AI summary
The disciples went to Galilee after the second week and likely to the Mount of the Beatitudes, where Jesus had appointed them. The five hundred brethren who saw Him at once had assembled by the promise of this manifestation, which was His most conspicuous resurrection appearance.
AI summary
Commenting on Matthew 28:16-20
And when they saw him, they worshipped him; but some doubted--certainly none of "the Eleven," after what took place at previous interviews in Jerusalem. But if the five hundred were now present, we may well believe this of some of them.