{From me} (par' emou). As in  1:13 . Paul was Timothy's
chief teacher of Christ. {Among many witnesses} (dia poll(936e)
martur(936e)). 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}
(parathou). Second aorist middle imperative of paratith(886d)i
( 1Ti 1:18 ) to deposit, same metaphor as parath(886b)(885c) 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.