Vincent's NT Word Studies
10. When he was alone. Mark only.They that were about him with the twelve. Mark only. Matthew and Luke, the disciples.
Robertson's NT Word Studies
4:10 {When he was alone} (hote egeneto kata monas). Only in Mark. Vivid recollection of Peter. Mark has also "they that were about him with the twelve" (hoi peri auton sun tois dwdeka), Matthew and Luke simply "the disciples." They did not want the multitude to see that they did not understand the teaching of Jesus.