A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
2 Corinthians 9:1
co2 9:1REASONS FOR HIS SENDING TITUS. THE GREATER THEIR BOUNTIFULNESS, THE MORE SHALL BE THE RETURN OF BLESSING TO THEM, AND THANKSGIVING TO GOD. (Co2 9:1-15)
For--connected with Co2 8:16 : "Show love to the messengers of the churches; for as concerns the ministration for the saints, it is superfluous for me to write to you who are so forward already."
write--emphatical: It is superfluous to "write," for you will have witnesses present [BENGEL].
2 Corinthians 9:2
co2 9:2ready a year ago--to send off the money, owing to the apostle's former exhortation (Co1 16:1-2).
your zeal--Greek, "the zeal from you," that is, on your part; propagated from you to others.
provoked--that is, stimulated.
very many--Greek, "the greater number," namely, of the Macedonians.
2 Corinthians 9:3
co2 9:3have I sent--we should say, "I send"; whereas the ancients put it in the past, the time which it would be by the time that the letter arrived.
the brethren-- (Co2 8:18, Co2 8:22) --Titus and the two others.
should be in vain in this behalf--"should be proved futile in this particular," however true in general (Co2 7:4). A tacit compliment, softening the sharp monition.
as I said--as I was saying (Co2 9:2).
2 Corinthians 9:4
co2 9:4if they of Macedonia--rather as Greek, "if Macedonians."
unprepared--with your collection; see Co2 9:2, "ready," Greek, "prepared."
we, not to say ye--Ye would naturally feel more ashamed for yourselves, than we (who boasted of you) would for you.
confident boasting--The oldest manuscripts read simply "confidence," namely, in your liberality.
2 Corinthians 9:5
co2 9:5that they would go before--Translate, "that they should," &c.
whereof ye had notice before--rather, "promised before"; "long announced by me to the Macedonians" (Co2 9:2) [BENGEL]. "Your promised bounty" [ELLICOTT and others].
not as of covetousness--Translate, "not as matter of covetousness," which it would be, if you gave niggardly.
2 Corinthians 9:6
co2 9:6I say--ELLICOTT and others supply the ellipsis thus: "But remember this."
bountifully--literally, "with," or "in blessings." The word itself implies a beneficent spirit in the giver (compare Co2 9:7, end), and the plural implies the abundance and liberality of the gifts. "The reaping shall correspond to the proportions and spirit of the sowing" [BENGEL]. Compare Eze 34:26, "Showers of blessing."
2 Corinthians 9:7
co2 9:7according as he purposeth in his heart--Let the full consent of the free will go with the gift [ALFORD]. Opposed to "of necessity," as "grudgingly" is opposed to "a cheerful giver" (Pro 22:9; Pro 11:25; Isa 32:8).
2 Corinthians 9:8
co2 9:8all grace--even in external goods, and even while ye bestow on others [BENGEL].
that--"in order that." God's gifts are bestowed on us, not that we may have them to ourselves, but that we may the more "abound in good works" to others.
sufficiency--so as not to need the help of others, having yourselves from God "bread for your food" (Co2 9:10).
in all things--Greek, "in everything."
every good work--of charity to others, which will be "your seed sown" (Co2 9:10).
2 Corinthians 9:9
co2 9:9As it is written--realizing the highly blessed character portrayed in Psa 112:9.
He--the "good man" (Psa 112:5).
dispersed--as seed sown with full and open hand, without anxious thought in what direction each grain may fall. It is implied also that he has always what he may disperse [BENGEL]. So in Psa 112:9.
the poor--The Greek word is found here only in New Testament, "one in straitened circumstances, who earns his bread by labor." The word usually employed means "one so poor as to live by begging."
his righteousness--Here "beneficence": the evidence of his being righteous before God and man. Compare Deu 24:13; Mat 6:1, "alms"; Greek, "righteousness."
remaineth--unexhausted and unfailing.
2 Corinthians 9:10
co2 9:10Translate, as in Isa 55:10, "He that ministereth (supplieth) seed to the sower and bread for food" (literally, "bread for eating").
minister--rather future, as the oldest manuscripts, "Shall minister (supply) and multiply."
your seed--your means for liberality.
the fruits of your righteousness--the heavenly rewards for your Christian charity (Mat 10:42). Righteousness shall be itself the reward, even as it is the thing rewarded (Hos 10:12; Mat 5:6; Mat 6:33).
2 Corinthians 9:11
co2 9:11Compare Co2 9:8.
bountifulness--Greek, "single-minded liberality." Translated "simplicity," Rom 12:8.
causeth through us--literally, "worketh through us"; that is, through our instrumentality as the distributors.
thanksgiving--on the part of the recipients.
2 Corinthians 9:12
co2 9:12Greek, "The ministration of this public service (on your part) is not only still further supplying the wants of the saints (besides the supplies from other quarters), but is abounding also (namely, in respect to relieving the necessities of others in poverty) through many thanksgivings to God."
2 Corinthians 9:13
co2 9:13by--through occasion of.
experiment--Translate, "the experience" [ELLICOTT and others]. Or, "the experimental proof" of your Christian character, afforded by "this ministration."
for your professed subjection--Greek, "for the subjection of your profession"; that is, your subjection in accordance with your profession, in relation to the Gospel. Ye yield yourselves in willing subjection to the Gospel precepts, evinced in acts, as well as in profession.
your liberal distribution--Greek, "the liberality of your contribution in relation to them," &c.
2 Corinthians 9:14
co2 9:14Translate, "Themselves also with prayer for you, longing after you on account of the exceeding grace of God (resting) upon you." English Version is, however, good sense: They glorify God (Co2 9:13) by the experimental proof, &c., "and by their prayer for you." But the Greek favors the former.
2 Corinthians 9:15
co2 9:15his unspeakable gift--the gift of His own Son, which includes all other inferior gifts (Co2 8:9; Rom 8:32). If we have received from God "His unspeakable gift," what great thing is it, if we give a few perishing gifts for His sake?