1 Corinthians 16:3

“And when I come, etc.] To Corinth, as he intended very quickly: whomsoever you shall approve by your letters; that is, such persons as this church should approve, and choose, and fix upon as proper persons to go with their collection; which approbation and choice they would signify by letters to the church, and principal men of it in Jerusalem, giving them a character as men of probity and faithfulness: them will I send. The Syriac, Arabic, and Ethiopic versions join the phrase, “by letters”, to this clause; according to which reading the sense is, such as the church should choose for this service, the apostle would send with letters of commendation from him, to the elders and church at…”

“approve by your letters--rather translate, "Whomsoever ye shall approve, them will I send with letters": namely, letters to several persons at Jerusalem, which would be their credentials. There could be no need of letters from them before Paul's coming, if the persons recommended were not to be sent off before it. Literally, "by letters"; an abbreviated expression for "I will send, recommending them by letters" [GROTIUS]. If English Version be retained, the sense will be, "When I come, I will send those whom by your letters, then to be given them, ye shall approve." But the antithesis (opposition or contrast) to Paul himself (Co1 16:4) favors GROTIUS' view. So "by" means with (Rom 2:27); and…”

“Whomsoever ye shall approve by your letters - There has been great variety of opinion in regard to the proper construction of this verse. Macknight supposes that the “letters” here referred to were not letters either to or from the apostle, but letters signed and sent by the congregation at Corinth, designating their appointment and their authority. With this interpretation Doddridge coincides; and this is required by the usual pointing of the Greektext, where the comma is inserted after the word letters, as in our translation. But a different interpretation has been proposed by inserting the comma after the word “approve,” so that it shall read, “Whom you approve, or designate, them I will…”

“when: Co1 4:19-21, Co1 11:34 whomsoever: Act 6:1-6; Co2 8:19-24 liberality: Gr. gift, Co2 8:4, Co2 8:6, Co2 8:19 1 Corinthians 16:4”