Today, a Greater Double, the Feast of the Holy Guardian Angels, the antiphon for the Benedictus in both the Breviary and the Liturgy of the Hours draws on Hebrews 1:14 to describe the Angels as leitourgika Spirits sent for diakonia. Is this why there is an iconographical convention of showing angels wearing dalmatics? Has anybody ever thought of using this to defend the (corrupt?) medieval practice whereby Byzantine Bishops wear not chasubles but dalmatics by saying that a Bishop is the Angel (see Rev 2:1 etc. and cf apostellomena of Heb1:14) of his Church?
[By the way, I have an ikon of the 1920s Bishop of Aegina, S Nektarios, wearing a chasuble; Although I know that Byzantine bishops do sometimes celebrate in a phelonion (and omophorion), I rather suspect this may be a delightful example of the conservatism of Byzantine iconography. He is also wearing a black hat; I assume it is his monastic hat.]
Incidentally, in this antiphon both the Breviary and LH change a very clear future (tous mellontas cleronomein which becomes capient haereditatem in both Vulgates) to a present capiunt: 'those who are already inheriting salvation'. Was there a nest of prescient adherents of C H ('Realised Eschatology') Dodd among the sixteenth century liturgists who put this office together?