Mary - 19:21
"It is so,"he said, "Your Lord said, ´It is easy for me. We will make him a sign for the people and a mercy from Us. This is a matter that has already been decided."
The same expression "Mercy" for Prophet Muhammad:
Mary/19:16
And mention Mary in the Book. She was separated from her family and withdrew to a place on the eastern side.
Mary/19:17
She drew a veil between her and them. Then We sent Our Spirit to her and she was formed before Us as a perfect human being.
Mary/19:18
"I seek refuge from you to the Most Merciful,"she said, "if you are righteous. . ."
Mary/19:19
"(The angel said:) "I am a messenger from your Lord, commissioned to give you a pure son."
Mary/19:20
"He said, "How can I have a son when no human hand has touched me and I have not been unchaste?"
Mary/19:21
"It is so,"he said, "Your Lord said, ´It is easy for me. We will make him a sign for the people and a mercy from Us. This is a matter that has already been decided."
The Repentance/9:61
"And some of them offend the Prophet, saying: "He is an ear (that gathers news)". Say: "He is an ear of good for you. He believes in Allah and trusts in those who believe. And a mercy for the believers among you. Those who offend the Messenger of Allah will have a painful torment."