2 Corinthians 9:14

καὶ αὐτῶν δεήσει ὑπὲρ ὑμῶν ἐπιποθούντων ὑμᾶς. The construction is uncertain: but it is clumsy to take δεήσει back to δοξάζοντες, ‘glorifying God by their prayer’; and still more so to take it back to περισσεύουσα, ‘abounding in their prayer.’ More probably αὐτῶν ἐπιποθούντων is a gen. absol. (comp. 2 Corinthians 4:18) adding the thought that (while the Corinthians exhibit their goodwill by their bounty) the recipients of the bounty exhibit their goodwill by intercession for the donors; while they themselves also, with supplication on your behalf, long after you, on account of the exceeding grace of God upon you. To make δεήσει depend on ἐπί (2 Corinthians 9:13) is grammatically possible, but yields no good sense. Would the Judean Christians glorify God for their own prayer? The word δέησις implies personal need (Luke 1:13; James 5:16; 1 Peter 3:12), and is often used of intercession, whether to God or to man (Romans 10:1; Philippians 1:4; 2 Timothy 1:3). See Lightfoot on Philippians 4:6, and Trench, Syn. § li.

τὴν ὑπερβάλλουσαν χάριν τοῦ θεοῦ ἐφʼ ὑμῖν. This is explained by πᾶσαν χάριν περισσεῦσαι in 2 Corinthians 9:8. The play of words between χάριν τοῦ θεοῦ and χάρις τῷ θεῷ (2 Corinthians 9:15) should be noted.