Vincent's NT Word Studies
1. Forbear (stegontev). Lit. no longer forbearing. See on 1 Corinthians ix. 12; LXX, Sir. viii. 17. For Class. parall. Soph. O. C. 15; Elec. 1118; Eurip. Hippol. 844; Ion 1412. He means that his longing for some personal communication from the Thessalonians became intolerable.To be left - alone (kataleifqhnai - monoi). Implying, as we sent (ver. 2) and I sent (ver. 5), the previous presence of Timothy with him at Athens.
Robertson's NT Word Studies
3:1 {When we could no longer forbear} (meketi stegontes). stegw is old verb to cover from stege, roof (#Mr 2:4), to cover with silence, to conceal, to keep off, to endure as here and #1Co 9:12; 13:7. In the papyri in this sense (Moulton and Milligan's _Vocabulary_). meketi usual negative with participle in the _Koin‚_ rather than ouketi. {We thought it good} (eudokesamen). Either literary plural as in #2:18 or Paul and Silas as more likely. If so, both Timothy and Silas came to Athens (#Ac 17:15f.), but Timothy was sent ({we sent}, epemyamen, verse #2) right back to Thessalonica and later Paul sent Silas on to Beroea or Thessalonica (verse #5, {I sent}, epempsa). qen both Silas and Timothy came from Macedonia to Corinth (#Ac 18:5). {Alone} (monoi). Including Silas. {God's minister} (diakonon tou qeou). See on ¯Mt 22:13 for this interesting word, here in general sense not technical sense of deacon. Some MSS. have {fellow-worker} (sunergon). Already {apostle} in #2:7 and now {brother, minister} (and possibly {fellow-worker}).