Commemorated September 16 (New Calendar) September 29 (Old Calendar)
Also May 27, for the uncovering and transfer of his relics with Saints Photius and Jonah

Saint Cyprian was from Tarnovo. Rostov names him a Serb. He was a man of holy life, learned in the sacred books, and a teacher of his flock. He told them to keep the fear of God, to turn from empty talk, and to hold to prayer and true repentance. He loved a quiet life at Golentishchevo, built a church there to the Three Hierarchs, ordained bishops and priests, and copied and translated many holy books from Greek into Slavonic. Four days before his death he wrote a farewell letter, forgiving all and asking their forgiveness. It was to be read over his grave. He reposed on September 16, in the year 1406, with a prayer of thanks on his lips.

The memory in St. Demetrius of Rostov does not preserve his spoken words from the letter.

Who stood with him

Patriarch Philotheus of Constantinople set him first over Kiev and Lithuania, and after Saint Alexis he became metropolitan of all Russia. He suffered much from the great prince before he was received in Moscow in 1390, under Basil Dimitrievich. The bishops and those near him were charged to read his farewell letter at his burial.

He spent his last strength on books, prayer, and a quiet word of forgiveness.

We ask his prayers when the Church is divided, when service-books must be kept true, and when we need to forgive before we die.

Pray for us

Troparion, Tone 4
“In truth you were revealed to your flock as a rule of faith,
an image of humility and a teacher of abstinence;
your humility exalted you;
your poverty enriched you.
Hierarch Father Cyprian,
entreat Christ our God
that our souls may be saved.”

The OCA page for September 16 does not print a separate kontakion.

Saint Cyprian, pray for us.

Sources

St. Demetrius of Rostov, Lives of the Saints, September 16.
https://azbyka.ru/otechnik/Dmitrij_Rostovskij/zhitija-svjatykh/794

Orthodox Church in America, Repose of Saint Cyprian, Metropolitan of Moscow and All Russia.
https://www.oca.org/saints/lives/0213/09/16/102627-repose-of-saint-cyprian-metropolitan-of-moscow-and-all-russia

This site is a lamp, not a parish. Listen to the life. Then find a living Orthodox church and ask a priest to pastor you.
https://pieceofhumanity.com/find-a-parish/