Uwais al Qarani was a Yemeni contemporary and devotee of the Prophet Mohammed – arguably his most devoted student, and yet they never met in person. The Prophet knew of Uwais on the inner planes, and when asked why someone so much in love with him did not come to visit him, he said that two things prevented Uwais: his ecstatic state and his obedience to the Prophet’s rules of conduct, as he herded camels all day and spent what he earned to care for his old and paralysed mother. When the Prophet was preparing for his death, he was asked who should receive his cloak, and he said it must go to Uwais al Qarani.

Uwais al Qarani said :
Safety is in solitude, and solitude is that state in which nothing but God is found in one’s heart.
Taking solitude literally is a mistake.
It behooves you to watch your heart,
so that no other may enter.