Verses  21-23  form a sort of postscript with greetings
from Paul's companions in Corinth. Timothy was with Paul in
Macedonia ( 2Co 1:1 ) before he came to Corinth. Lucius may be
the one mentioned in  Ac 13:1 . Jason was once Paul's host ( Ac
17:5-9 ) in Thessalonica, Sosipater may be the longer form of
Sopater of  Ac 20:4 . They are all Paul's fellow-countrymen
(suggeneis).