More literally and better, imitators. Only once outside of Paul's writings, Heb 6:12. Comp. 1Th 3:9; 2Th 3:7; 1Co 4:16; 1Co 11:1; Gal 4:12; Phi 3:17; Phi 4:9.
And of the Lord
Guarding against any possible imputation of self-assertion or conceit. Comp. 1Co 11:1.
Tribulation (θλίψει)
See on Mat 13:21. Referring especially to persecutions at the hands of the Jews (Act 17:5 ff.), which probably continued after Paul's departure from Thessalonica.