Saints Mark the Grave-Digger, Theophilus and John are mentioned in the Kiev Caves Paterikon. Two brothers being monastics, Saints Theophilus and John, so loved each other that they prevailed upon Saint Mark to prepare a double grave so they could be buried side by side.

Many years later, the older of the two brothers was away on monastery business. During this time his brother John fell ill and died. Several days later, Saint Theophilus returned and went with the brethren to view his brother’s body. Seeing that he lay at the higher place in their common grave, he became indignant with Saint Mark and said, “Why did you put him in my place? I am older than he.”

The cave-dweller Mark, bowed humbly to Saint Theophilus and asked that he forgive him. Turning to the dead man, he said, “Arise, give this place to your older brother, and you lie down in the other place.” And the dead man moved to the lower place in the grave. Seeing this, Saint Theophilus fell down at the knees of Saint Mark begging his forgiveness. The cave-dweller Mark told Theophilus that he ought to be concerned for his own salvation, because soon he would join his brother in that place.

Hearing this, Saint Theophilus became terrified and decided that he would soon die. He gave away everything that he possessed, keeping only his mantle, and every day he awaited the hour of death. No one was able to stop his tears, nor to tempt him with tasty food. Tears were his bread by day and by night (Ps 41/42:3). God granted him several years more for repentance, which he spent in fasting and lamentation. He even went blind from continuous weeping.

Saint Mark forsaw the hour of his death and told Theophilus he would soon depart this life. Theophilus pleaded, “Father, either take me with you, or restore my sight.” Saint Mark said to Theophilus, “Do not desire death, it shall come in its own time, even if you do not wish it. Let this be the sign of your impending end: three days before you depart this world, your eyesight will return.”

The words of the saint were fulfilled. The body of Saint Theophilus was placed in the Antoniev Cave in the grave together with his brother Saint John, near the relics of Saint Mark. Their memory is celebrated also on September 28 and on the second Sunday of Great Lent.

Source:

https://oca.org/saints/lives/2016/12/29/103685-venerable-theophilus-of-the-kiev-near-caves