There are two icon types that appear visually similar but should not be confused, because they are really quite different in what they represent.
Here is the first, in a 17th century example from the Stroganov School, by Nikifor Istomin Savin. It bears a title inscription reading:
Святы Ангел хранит спящего человека душу и тело
Svyatuiy Angel Gospoden Khranit Spyashchego Cheloveka Dushu i Telo
“The Holy Angel of the Lord Protects the Sleeping Man, Soul and Body.”
It depicts a generic righteous man asleep on his bed. The Guardian Angel (at left), watches over him, with sword in one hand and cross in the other. A demon, seeing this protector, flees away at right. Above the sleeping man is an icon of the Deisis.
Here is another and later example of the same type, though the inscription is slightly different:
“The Holy Guardian Angel Protects the Sleeping Man.”:
It has additions — the image of the same man while awake, praying before the Deisis icon. The Guardian Angel too is seen a second time (at far right), recording this good deed of the man on his scroll, along with all the rest of his actions.
Both versions are sometimes called simply “The Sleep of the Righteous.”
But be careful. Here — as mentioned — is a visually similar type, but it is not at all the same in meaning as the two shown above, and should never be confused with them. It is an Old Believer image of a type popular in the Guslitsa (Гуслица) region — a center of the Old Belief — in the 19th century.
It is easy to see why some misidentify this icon as the first type. There is a man on a bed, an angel standing by him, and an icon on the wall behind them. But this type is actually an icon of Ioann Ogorodnik/Иоанн Огородник — “John the Gardener.”
The tale comes from the Prolog, November 8th. It is said that there was once a gardener named John, who was very concerned about the poor. Consequently, he kept only a small part of his income, and gave the rest away in charity. But after this had been going on for some time, John began to worry what would become of him when he got old, and if he were to become ill. So instead of giving away a good part of his money to the poor, he instead began to collect the silver coins for himself, to use in age and illness.
Soon — just as he feared, it seemed — he was stricken with an ailment. The flesh on his leg began to turn putrid and was covered with sores. He went to many doctors, and spent a huge amount of money, but none could cure him. Finally a doctor who was supposed to be the most skilled of all of them told him that there was nothing to be done but to cut the leg off. John had to agree, and the doctor was to come the next day and perform the operation.
That night, John was in tears. He prayed to Jesus:
Господи, помяни мои первые дела, когда я был щедр на милостыню, и исцели меня!»
“Lord, remember my first actions, when I was generous in charity, and heal me!
Hardly had he said this when an angel of God appeared before him, saying “Now, where is all the silver you had accumulated?”
John confessed he had sinned, and said that if the Lord would heal him, he would do so no more.
The angel then touched John’s leg (as shown in the icon above) and he was healed.
The next day when the doctor came to cut off the leg, he found John was not home. He asked where John was, and the reply came that John had left early, to work in his garden. The doctor set off for the garden, and when he arrived, there was John working away. Seeing this, the doctor exclaimed, “Blessed are the merciful, for they will obtain mercy.”