John Mark
Mark 3:13ESV·traditional attribution

And he went up on the mountain and called to him those whom he desired, and they came to him.

John Calvin Reformed @genevareformer

Mark 3:13. And he went up into a mountain. By this election he does not yet ordain them to be Apostles, to enter immediately into the discharge of their office, but merely admits them to enjoy his private instructions “Pour ses disciples et escoliers domestiques;” — “for his disciples and private scholars.” with a view to the apostleship.

Matthew Henry Presbyterian @wholebiblehenry

In these verses, we have, I. The choice Christ made of the twelve apostles to be his constant followers and attendants, and to be sent abroad as there was occasion, to preach the gospel. Observe, 1. The introduction to this call or promotion of disciples; He goes up into a mountain, and his errand thither was to pray.

Commenting on Mark 3:13-21

John Gill Reformed Baptist @doctorgill

And he goeth up into a mountain,.... Near Capernaum, being solitary, and a place of recess and retirement, "to pray", as Luke says, Luk 6:12, who adds, "and continued all night in prayer to God", notwithstanding the great fatigue of the day past.