For (οτ). Second causal conjunction (οτ) explanatory of the first οτ, like the two cases of οτ in Revelation 15:4.

They poured out (εξεχεαν). Second aorist active indicative of εκχεω with -αν instead of -ον.

Blood hast thou given them to drink (αιμα αυτοις δεδωκας πειν). Hαιμα (blood) is the emphatic word, measure for measure for shedding the blood of saints and prophets (Revelation 11:18; Revelation 18:24). Perfect active indicative of διδωμ, and so a permanent and just punishment. Πειν is the abbreviated second aorist active infinitive of πινω for πιειν (επιον). It is the epexegetical infinitive after δεδωκας. There was no more drinking-water, but only this coagulated blood.

They are worthy (αξιο εισιν). "Terrible antithesis" (Swete) to Revelation 3:4. The asyndeton adds to it (Alford).