A.T. Robertson Commentary 2 Corinthians 2:4

"For out of much affliction and anguish of heart I wrote unto you with many tears; not that ye should be made sorry, but that ye might know the love that I have more abundantly unto you." — 2 Corinthians 2:4 (ASV)

Anguish (συνοχης). Ablative case after εκ (out of). Old word from συνεχω, to hold together. So contraction of heart (Cicero, contractio animi), a spiritual angina pectoris. In N.T. only here and Lu 21:25.

With many tears (δια πολλων δακρυων). He dictated that letter "through tears" (accompanied by tears). Paul was a man of heart. He writes to the Philippians with weeping (κλαιων) over the enemies of the Cross of Christ . He twice mentions his tears in his speech at Miletus (Acts 20:19–31).

But that ye might know the love (αλλα την αγαπην ινα γνωτε). Proleptic position of αγαπην and ingressive second aorist active subjunctive γνωτε, come to know.