{I wrote this very thing} (egrapsa touto auto). Is this
(and egrapsa in verses  4,9,12 ) the epistolary aorist
referring to the present letter? In itself that is possible as
the epistolary aorist does occur in the N.T. as in  8:18  9:3 
(Robertson, _Grammar_, p. 854f.). If not epistolary aorist as
seems improbable from the context and from  7:8-12 , to what
Epistle does he refer? To  1Co 5  or to a lost letter? It is
possible, of course, that, when Paul decided not to come to
Corinth, he sent a letter. The language that follows in verses
 3,4  7:8-12  can hardly apply to I Corinthians. {Should have
sorrow} (lup(886e) sch(935c)). Second aorist (ingressive) active
subjunctive of ech(935c), should get sorrow, after hina m(885c)
negative final particles. {From them of whom} (aph' h(936e)).
Antecedent omitted, apo tout(936e) aph' h(936e) (from those from whom).
{I ought} (edei me). Imperfect for unrealized present
obligation as often and like English. {Having confidence}
(pepoith(9373)). Second perfect active participle of peith(935c)
( 1:9 ).