{That ... may be required} (hina ... ekz(8874)(8874)h(8869)).
Divinely ordered sequence, first aorist passive subjunctive of
ekz(8874)e(935c), a late and rare verb outside of LXX and N.T.,
requiring as a debt the blood of the prophets. {Which was shed}
(	o ekkechumenon). Perfect passive participle of ekche(935c) and
ekchunn(935c) (an Aeolic form appearing in the margin of Westcott
and Hort here, ekchunnomenon, present passive participle). If
the present passive is accepted, it means the blood which is
perpetually shed from time to time. {From the foundation of the
world} (apo katabol(8873) kosmou). See also  Mt 25:34  Joh 17:24  Eph 1:4 , etc. It is a bold metaphor for the purpose of God.