## the ones who had been sent out ##

"the twelve apostles that Jesus had sent out"

## returned ##

"came back to where Jesus was"

## they told him ##

"the apostles told Jesus"

## everything they had done ##

This refers to the teaching and healing that they did when they went to the other cities.

## And taking them with him, he went away by himself ##

This could be translated as "He took them with him and they went by themselves." Jesus and his apostles went away by themselves.