I've found some writings by modern Copts that mention that this is a good prayer to pray, such as some of the writings of HG Bishop Mettaous, but nothing that indicates that it is a part of Coptic tradition. Can anyone provide evidence of it being used historically in the Coptic Church?
Some one told me that when Pope Kyrollos was their father in confession, obviously many years ago, he told them to stop praying the Agpeya and only pray the Jesus prayer until he told them otherwise.
When we sing Ps 150 at every Sacrament, including every Liturgy we, conclude with "O my Lord Jesus Christ, the Son of God, hear us and have mercy upon us."
As Salpy indicated, the exact phrase known as "the Jesus prayer" by the EO today has not been such a rigid formula. But the Arrow prayer, a short, one line prayer repeated in times of distress, in combat of thoughts, or even ceaselessly, comes right from the Egyptian Desert from the earliest ascetic fathers. Wether just "Lord have mercy", a single like from a Ps, or "O my Lord, Jesus Christ, the Son of God, have mercy on me a sinner", the arrow prayer is an authentic part of our pre-schism tradition.