St. Maximus the Greek (+ 21 January 1556) was imprisoned in Russia, banished to the Monastery of Volokolamsk, where he suffered from hunger, bitter cold and all kinds of torments. There he was bereft of everything, even being deprived of Holy Communion and books, yet prayer alone sustained him. The Lord did not abandon him, but one day an angel appeared to him and said: “Have patience! You will be delivered from eternal torment by the sufferings here below.” To thank God for this heavenly consolation, St. Maximus composed a poetical canon in honor of the Holy Spirit. Deprived of paper and pen, he wrote it on the walls of his cell in charcoal. This canon is sung on the Monday of the Holy Spirit in certain Russian and Serbian monasteries.