The Book Pertaining to Repentance and Exhortation to Repentance (Kitab Al-Tauba)
Muslim :: Book 37 : Hadith 6617
Al-Bara' b. 'Azib reported Allah's Messenger (may peace be upon him) as saying that Allah's Messenger (may peace be upon him) said: What is your opinion about the delight of a person whose camel loaded with the provisions of food and drink is lost and that moves about with its nosestring trailing upon the waterless desert in which there is neither food nor drink, and lie wanders about in search of that until he is completely exhausted and then accidentally it happens to pass by the trunk of a tree and its nosestring gets entangled in that and he finds it entangled therein? He (in response to the question of the Holy Prophet) said: Allah's Messenger, he would feel highly delighted. Thereupon Allah's Messenger (may peace be upon him) said. By Allah, Allah is more delighted at the repentance of His servant than that person (as he finds his lost) camel.