Colossians 4:10

Aristarchus my fellow prisoner saluteth you
This man was a man of Macedonia, and a Thessalonian; ( Acts 19:29 ) ( 20:4 ) which hinders not but that he might be of the circumcision, or a Jew, as is suggested in the following verse; for he might be born at Thessalonica, and yet be of Jewish parents; nor is his Greek name any objection to it, for the Jews themselves say, that the greatest part of the Israelites that were out of the land, their names are as the names of strangers ^F12: he was a constant companion of the apostle, and one of his fellow labourers, as in ( Philemon 1:24 ) and now a prisoner with him at Rome; and who having some knowledge of the members of the church at Colosse, takes this opportunity of sending his Christian salutation to them:

and Marcus, sister's son to Barnabas;
the same with John Mark, whose mother's name was Mary, said here to be sister to Barnabas, ( Acts 12:12 Acts 12:24 ) concerning whom there was a difference between Paul and Barnabas, ( Acts 15:37 Acts 15:38 ) , and is the same Mark that wrote the Gospel, and was converted by the Apostle Peter, ( 1 Peter 5:13 ) and who is said to have received his Gospel from him; he is also mentioned ( 2 Timothy 4:11 ) ( Philemon 24 ) . The Arabic version calls him here, the "brother's son of Barnabas": and the Syriac version, (hdd rb) , "his uncle's son": however, Barnabas being so great a man as he was, and so well known, it added some credit to Mark, that he was a relation of his:

touching whom ye received commandments;
not concerning Barnabas, but Mark, concerning whom they had had letters of commendation, either from Barnabas or from Paul, to this purpose:

if he come unto you, receive him;
for this was either the substance of those letters, or what the apostle now adds of his own, for the further confirmation of them; and that they might more readily and honourably receive him, when he should come unto them.