John Gill's Bible Commentary Ver. 7. Therefore, brethren, we were comforted over, you , etc.] Or in you, as the Vulgate Latin version; or from you, as the Arabic; or by you, as the Syriac; or for you, as the Ethiopic; that is, on account of them, either by what they had heard was in them, or had heard from them.
This gave abundant consolation in all our affliction and distress : which they met with at Corinth, where the apostle laboured with his own hands, and ministered to his own, and the necessities of others, and was greatly opposed, reproached, and persecuted; (see Acts 18:3,6,9,10,12), but the news of the good estate and condition the Thessalonians were in, was a great relief and comfort to him, particularly their faith: by your faith : by the report of it, that it grew exceedingly, and that they walked in the truth; (see 1 John 5:4). The Alexandrian copy reads, in all your distress and affliction, and by your faith.
Matthew Henry Commentary
Verses 6-10 - Thankfulness to God is very imperfect in the present state; but on great end of the ministry of the word is to help faith forward. Tha which was the instrument to obtain faith, is also the means of increasing and confirming it, namely, the ordinances of God; and a faith cometh by hearing, so it is confirmed by hearing also.
Greek Textus Receptus
δια 1223 PREP τουτο 5124 D-ASN παρεκληθημεν 3870 5681 V-API-1P αδελφοι 80 N-VPM εφ 1909 PREP υμιν 5213 P-2DP επι 1909 PREP παση 3956 A-DSF τη 3588 T-DSF θλιψει 2347 N-DSF και 2532 CONJ αναγκη 318 N-DSF ημων 2257 P-1GP δια 1223 PREP της 3588 T-GSF υμων 5216 P-2GP πιστεως 4102 N-GSF
Vincent's NT Word Studies
7. Affliction (anagkh). Rev. distress. The derivation from agxein to press tightly, to choke (Lightfoot, Ellicott) is doubtful. In the sense of urgency, distress, seldom in Class. See 1 Cor. vii. 26; 2 Corinthians vi. 4; xii. 10; Luke xxi. 23.
Robertson's NT Word Studies
3:7 {Over you} (ef' humin). epi with the locative, the basis on which the "comfort" rests. {In} (epi). Locative case again with epi. {Distress} (anagkei). {Physical necessity}, common sense in late Greek, choking (agcw, angor), and {crushing} trouble (qliyis, qlibw).