John Gill Commentary Acts 12:25

"And Barnabas and Saul returned from Jerusalem, when they had fulfilled their ministration, taking with them John whose surname was Mark." — Acts 12:25 (ASV)

And Barnabas and Saul returned from Jerusalem
Two of Beza's exemplars, the Complutensian edition and the Syriac version, add, "to Antioch"; and certain it is, that from there they were sent, and they returned there, for we find them there in the beginning of the next chapter:

when they had fulfilled their ministry ;
which was the carrying the relief, or the money collected by the Christians at Antioch, for the brethren in Judea, on account of the famine that was there:

and took with them John, whose surname was Mark :
the son of Mary, at whose house the disciples were met together, and praying; and where Peter first went, after he was delivered from prison, (Acts 12:12) him they brought with them from Jerusalem to Antioch, being a kinsman of Barnabas; and a man of promising gifts and usefulness, and judged to be a fit companion with them in their travels, for the spread of the Gospel.