Sahih Bukhari Volume 002, Book 023, Hadith Number 339.
Narated By Ibn Abbas : A person died and Allah's Apostle used to visit him. He died at night and (the people) buried him at night. In the morning they informed the Prophet (about his death). He said, "What prevented you from informing me?" They replied, "It was night and it was a dark night and so we disliked to trouble you." The Prophet went to his grave and offered the (funeral) prayer.