An epistle of Christ ministered by us (ἐπιστολὴ Χριστοῦ διακονηθεῖσα ὑφ' ἡμῶν)
An epistle written by Christ through our ministry; that is, you, as the converted subjects of our ministry, are an epistle of Christ. Others explain: an epistle of which Christ forms the contents, thus making the apostles the writers. For the expression ministered by us, compare 2Co 8:19, 2Co 8:20; 1Pe 1:12.
From μέλας black. Only here, 2Jo 1:12 (see note), and 3Jo 1:13.
Instead of ink.
Fleshy tables of the heart (πλαξὶν καρδίας σαρκίναις)
The best texts read καρδίαις the dative case in apposition with tables. Render, as Rev., tables which are hearts of flesh. Compare Eze 11:19; Jer 17:1; Jer 31:33. For of flesh, see on Rom 7:14.