A.T. Robertson Commentary 1 Timothy 1:16

"howbeit for this cause I obtained mercy, that in me as chief might Jesus Christ show forth all his longsuffering, for an ensample of them that should thereafter believe on him unto eternal life." — 1 Timothy 1:16 (ASV)

In me as chief (εν εμο πρωτω). Probably starts with the same sense of πρωτος as in verse 15 (rank), but turns to order (first in line). Paul becomes the "specimen" sinner as an encouragement to all who come after him.

Might shew forth (ενδειξητα). First aorist middle subjunctive (purpose with ινα) of ενδεικνυμ, to point out, for which see Eph 2:7 (same form with ινα).

Longsuffering (μακροθυμιαν). Common Pauline word (2 Corinthians 6:6).

For an ensample (προς υποτυπωσιν). Late and rare word (in Galen, Sext. Emp., Diog. Laert., here only in N.T.) from late verb υποτυποω (in papyri) to outline. So substantive here is a sketch, rough outline. Paul is a sample of the kind of sinners that Jesus came to save. See υποδειγμα in 2 Peter 2:6.