Vincent's NT Word Studies
2. Among many witnesses (dia pollwn marturwn). Dia through the medium of, and therefore in the presence of.Commit (paraqou). As a trust or deposit (paraqhkh). See on chapter i. 12,14. In Paul only 1 Cor. x. 27.
Faithful (pistoiv). Not believing, but trusty, as appears from the context. See on 1 John i. 9; Apoc. i. 5; iii. 14.
Able (ikanoi). In Pastorals only here. Very common in Luke and Acts: a few times in Paul. See on many, Rom. xv. 23.
Robertson's NT Word Studies
2:2 {From me} (par' emou). As in #1:13. Paul was Timothy's chief teacher of Christ. {Among many witnesses} (dia pollwn marturwn). Plutarch has dia in this sense and Field (_Ot. Norv._) suggests that it is a legal phrase "supported by many witnesses." Not mere spectators, but testifiers. See Paul's use of dia #1Th 4:2; 2Co 2:4; Ro 2:27; 14:20. Paul in #1Co 15:1-8 gives many witnesses of the resurrection of Christ. {Commit thou} (paraqou). Second aorist middle imperative of paratiqemi (#1Ti 1:18) to deposit, same metaphor as paraqeke in #1:12,14. "Deposit thou." {Faithful} (pistois). "Trustworthy," "reliable," as in #1Ti 1:12 of Paul himself. {Able} (hikanoi). Capable, qualified, as in #1Co 15:9; 2Co 2:16; 3:5. {Others also} (kai heterous). Not necessarily "different," but "others in addition." this is the way to pass on the torch of the light of the knowledge of God in Christ. Paul taught Timothy who will teach others who will teach still others, an endless chain of teacher-training and gospel propaganda.