Mark 3:19

And Judas Iscariot
So called to distinguish him from the other Judas; and is mentioned last for the following reason:

which also betrayed him;
and which action of his will ever render his name infamous among men. This man, with the rest, our Lord chose to be an apostle of his, though he knew he would betray him; in order to fulfil the purposes of God, the prophecies of the Old Testament, and bring on the work of man's redemption he came into the world to perform.

And they went into an house at Capernaum;
the house of Simon and Andrew, where Jesus used to be when there: they went home with him from the mountain; and from that time became his domestics, and were looked upon by him as his family, and were admitted to the greatest nearness and intimacy with him.