"Prayer of the Fathers" from the Holy Liturgy of St.
Mark known as "The Kyrillian," Eusebius: Hist.
Eccles. VII, 4 and 7; R. Payne: "The Holy Fire"
p.59; A. J. Butler: "The Ancient Coptic Churches of
Egypt," vol. II p. 302 where he says: "The name pope' orbaba' has given rise to much controversy,
but may probably be derived from Coptic ‘ ΠiαΠα’
(Pi-apa) or ‘ΠIαββα’ (Pi-abba)”
Copto-Arabic Ms. no. 253 Lit., Coptic Museum
Library, dated 1080 AM (1364 A.D.) folio 66r;
"Book of Consecrations"-section on Patriarchs,
copied from Coptic Mss. and pub. in Rome in 1761
A.D.