Albert Barnes Commentary Romans 16:22

"I Tertius, who write the epistle, salute you in the Lord." — Romans 16:22 (ASV)

I Tertius. Of Tertius nothing more is known than is mentioned here.

Who wrote this. It is evident that Paul employed an amanuensis to write this epistle, and perhaps he commonly did it. Tertius, who so wrote it, joins with the apostle in affectionate salutations to the brethren at Rome. To the epistle Paul signed his own name, and added a salutation in his own handwriting. Colossians 3:18, The salutation by the hand of me Paul; and in 2 Thessalonians 3:17, he says that this was done in every epistle. 1 Corinthians 16:21.

In the Lord. As Christian brethren.