Hadhrat Uwais Qarni, the Sun of the ummah and Candle of Islam, is one of the greatest Sufi shaikhs among the followers of the companions of the Prophet, peace be upon him. But he could not see the Prophet (s.a.w), partly because he was overwhelmed by hal (ecstatic rapture), and partly because of full devotion to his mother's service.
The Prophet, peace be upon him, told his companions that there was a man in Qarn by the name of Uwais, "who will intercede for as many men of my ummah on the Day of Judgement, as there are goats in Rabia and Mudhir tribes," (who were famous for huge flocks of goats). He also bade Hadhrat Umar and Ali, may Allah be pleased with them, to go and see Uwais who had the following signs: medium height, long hair and a white spot the size of a dirham on his left side, not caused by leprosy, and a white spot on his palm.
The Prophet (s.a.w) said, "When you meet him, convey my salaams to him and ask him to pray for my ummah."
After the Prophet (s.a.w) had passed away, Hadhrat Umar and Ali happened to be in Makkah. During his congregational address Hdhrat Umar turned to the people from Najd and asked, "Is there any man from Qarn among you?"
When they replied in affirmative, he enquired if there lived a person by the name of Uwais there. They said, "Yes he is crazy, lives alone and does not mix with people. He does not eat what people generally eat, and is not affected by happiness or sorrow. When people laugh he weeps, and when they weep he laughs."
Hadhrat Umar said, "I want to meet him."
They took Hadhrat Umar and Ali to the place where he lived, and found him saying his prayers (salat). When he finished his prayer, he wished them salaam and showed them the marks of recognition which the Prophet (s.a.w) had indicated. Hadhrat Umar and Ali delivered the Prophet's message to him and asked for doa' (prayer) for the ummah.
They remained there for some time. Uwais said, "I am sorry you had to travel all the way to see me. You should better go back now, for the Day of Dooms is near and we will meet again there without fear of parting; for now I am busy preparing for that day."
After Hadhrat Umar and Ali, may Allah be pleased with them, had left, Uwais's honour and esteem went up among his people; as a result of which he fled to Kufah and was no more seen by anybody except Harm bin Hayan and that only once. He reappeared during the battle of Siffin (between Hadhrat Ali and Hadhrat Muawiyah, may Allah be pleased with them).
He fought on the side of Hadhrat Ali and fell a martyr. He lived as a hameed (virtuous) and died a shaheed (martyr). He is reported to have said, "Safety lies in solitude". For the heart which is alone is attached with God and detached from all else. But do not go away with the idea that solitude means living alone. Since even in solitude, Satan is your companion and your nafs (lower self) is your overlord.
Real solitude lies in the love of God. He who loves God, is not disturbed by anything. But he who loves the world, has nothing to do with God. Real solitude is characteristic of the pious soul who finds peace in the verse "Alaisa Allah-u-Kaffin abdahu" (Is God not enough for the abd [true slave]?) [39:36]