Our Righteous Father Marcellus, Abbot of the Monastery of the Unsleeping Ones

Reading from the Synaxarion:

Saint Marcellus, who was from the city of Apamea in Syria, was born of
renowned parents. Adorned with virtue and learning, he succeeded Saint
Alexander to the abbacy of the Monastery of the Unsleeping about the year
460. This monastery was so named because the monks there were divided
into three ranks, and took turns in succession for the execution of
the sacred services both day and night, and thus ceaselessly sent up
praise to God, without any lapse. The author of this practice was the
aforementioned Alexander. As the biographer of both these Saints writes: "Later,
a venerable monastery was established near the mouth of Pontus -
that is, the place where the Black Sea tracts into the Bosphorus - and
he introduced a rule that, though new, was superior to any found
elsewhere; that is, that henceforth they should never be any cessation in
the hymnody offered to God, but that through an unbroken succession
of those that served in turn, there should be achieved this
continuous and unceasing glorification of our Master."

Apolytikion in the Plagal of the Fourth Tone
The image of God, was faithfully preserved in you, O Father. For you
took up the Cross and followed Christ. By Your actions you taught us
to look beyond the flesh for it passes, rather to be concerned about
the soul which is immortal. Wherefore, O Holy Marcellus, your soul
rejoices with the angels.

Kontakion in the Fourth Tone
Thou clad in a mortal body, O Marcellus most wise, thou strovest to
emulate the Angels' choirs in divine perpetual hymnody. And as an
unsleeping shepherd of thy monastics, thou wast an example of true prayer
and devoutness; O Father, intercede with the Lord, that He would save
our souls.