Mark 5:37

‘And he allowed no one to follow with him except Peter, and James and John, the brother of James.'

The crowds were dismissed, and no doubt departed willingly. They recognised the respect due to the dead and it was now clear that there would be no miracle. But Jesus also left most of His disciples behind. Possibly so that they could ensure that no one disobeyed His requirement for privacy.

‘Except Peter, James, and John, the brother of James.' These three are regularly singled out to attend Him at His most sacred moments, both as helpers and as witnesses (Mark 9:2; Mark 14:33), and He did not want to further distress the household by crowding the house out. But the fact that He took them demonstrates that while it was to be kept quiet for the present, He wanted witnesses for the future. He wanted them to learn. It is probably significant that these three were also called to be witnesses to His transfiguration (Mark 9:2). He would not have done this just for an ordinary healing. There what had happened was not to be revealed until after His resurrection. Perhaps it was also so here.

This is a Marcan note slightly in advance describing the instructions that He gave. Once they arrived at the house only the three must go in with Him.