The best grammatical note on this present participle is that found in
Moulton, Einleitung 206, which places the tense of τοὺς ἁγιαζομένους in relation to the tense of τετελείωκεν (we have the same construction in 2:11):
what is a completed fact for Christ in regard to us is in progressing relation
to us, the objects concerned. If no relation of tense is intended, why did the
writer not use a noun, say τοὺς ἁγίους or some other? We
also note that the perfect used in v. 10, “we have been sanctified,” is now
repeated, but it is not restricted to “we” (writer and readers) but includes
all who at any time experience the sanctifying power of Christ’s completed
offering and its completed effect on them. (R. C. H. Lenski, The Interpretation of the Epistle to the
Hebrews and of the Epistle of James [Columbus, Ohio: Lutheran Book Concern,
1938], 337-38)
Further Reading:
Refuting
Tony Brown on the theology of the Epistle to the Hebrews
