Stephen Hughes wrote:The real point if interest here is the διὰ σοῦ. Is it a spark that glowed for a moment then grew cold, or is this the earliest witness to what would become για σου in the Modern idiom.
BAGS has a special note about this papyrus down the bottom on the second page. I guess it "should" be υπέρ σου down the bottom of the second column.
Well, BDAG has:
⑤ At times διά w. gen. seems to have causal mng. (Rdm. 142; POxy 299, 2 [I A.D.] ἔδωκα αὐτῷ διὰ σοῦ=because of you; Achilles Tat. 3, 4, 5 διὰ τούτων=for this reason; in Eng. cp. Coleridge, Anc. Mariner 135–36: Every tongue thro’ utter drouth Was wither’d at the root, s. OED s.v. ‘through’ I B 8) διὰ τῆς σαρκός because of the resistance of the flesh Ro 8:3.—2 Cor 9:13.—On the use of διά w. gen. in Ro s. Schlaeger, La critique radicale de l’épître aux Rom.: Congr. d’ Hist. du Christ. II 111f.
Arndt, W., Danker, F. W., & Bauer, W. (2000). A Greek-English lexicon of the New Testament and other early Christian literature. Chicago: University of Chicago Press.
I took it instrumentally, "through you" meaning that the writer had used the individual to whom he was writing to make the payment, but since he expects the money back it makes more sense to see it as BDAG does, or perhaps "for you.." as you seem to suggest above. But I doubt that it's the ancestor her of για σου!