From Dom Guéranger's The Liturgical Year.
The soldier Mennas was a native of Egypt, and after his martyrdom became the protector of Alexandria. It is not a rare thing to find, even at this date, phials formerly brought by pilgrims to be filled with oil from the lamp burning before his tomb. Let us say with the Church:
Prayer
Praesta quaesumus omnipotens Deus: ut qui beati Mennae Martyris tui natalitia colimus, intercessione ejus in tui nominis amore roboremur. Per Dominum.
Grant we beseech thee, O Almighty God, that we who celebrate the festival of blessed Menuas thy martyr, may by his intercession be strengthened in the love of thy name. Through our Lord.