The church is to appoint some of their own members to carry their gift to Jerusalem. In this way no one will be able to accuse Paul of enriching himself through the Gentile churches (see also 2 Corinthians 8:20–21). The delegated church members will be given a letter to recommend them to the church in Jerusalem. (This was common practice at the time; see Acts 9:2; Acts 15:23–29; Acts 22:5.) Although it is not said who will write this letter, we can have reasonable certainty that it will be Paul himself, since he is well known and respected by the church in Jerusalem.
In 2 Corinthians we read of a respected brother
who was appointed by the churches
to accompany the apostles as they travelled to Jerusalem with the collection money (2 Corinthians 8:18–19). Whether this brother was a Corinthian church member, or only someone whom the Corinthians knew and trusted, he seems to have been entrusted with the task of taking their contribution to Jerusalem.
Finally, note that Paul calls the Corinthians’ contribution a gift.
He uses the Greek word charis, a word that is also used for the grace and favour of God. In some contexts it can mean thanksgiving.
Indeed, Paul would later write to the Corinthians that their collection is overflowing in many thanksgivings to God
(2 Corinthians 9:12).
3 And when I arrive, I will send those whom you accredit by letter to carry your gift to Jerusalem.