There is a story about a Jew named Abul-Khair who was a well known physician. Once he was passing through a town alley when he heard somebody reciting:
اَحَسِبَ النَّاسُ اَنۡ یُّتۡرَکُوۡۤا اَنۡ یَّقُوۡلُوۡۤا اٰمَنَّا وَہُمۡ لَا یُفۡتَنُوۡنَ1
Although he was a Jew, he leaned against a wall with his hands, bowed his head and started crying. Afterwards, he went home and while asleep, he dreamt that the Holy Prophet (peace and blessings of Allah be on him) visited him and said, ‘O Abul-Khair, it is strange that a person with dignity and grace like you is not a Muslim.’ When he woke up in the morning, he made a public announcement in the city that he was embracing the religion of Islam.
(Malfuzat, Vol. 9, p. 201)
1 Do men think that they will be left alone because they say, ‘We believe,’ and they will not be tried? (Surah al-‘Ankabut, 29:3). [Publisher]