Muwatta Malik, Book 3, Hadith 75 (USC-MSA) ⓘ

Yahya related to me from Malik from Abdullah ibn Abi Bakr that a man from the Ansar was praying in a garden of his in Quff, one of the valleys of Madina, during the date season and the palms' branches were weighed down with fruit on all sides. He looked at them and what he saw of their fruits amazed him. Then he went back to his prayer and he did not know how much he had prayed. He said, "A trial has befallen me in this property of mine." So he went toUthman ibn Affan, who was the khalifa at the time, and mentioned it to him and said, "It is sadaqa, so give it away in the paths of good." Uthman ibn Affan sold it for fifty thousand and so that property became known as the Fifty.

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَكْرٍ، أَنَّ رَجُلاً، مِنَ الأَنْصَارِ كَانَ يُصَلِّي فِي حَائِطٍ لَهُ بِالْقُفِّ - وَادٍ مِنْ أَوْدِيَةِ الْمَدِينَةِ - فِي زَمَانِ الثَّمَرِ وَالنَّخْلُ قَدْ ذُلِّلَتْ فَهِيَ مُطَوَّقَةٌ بِثَمَرِهَا فَنَظَرَ إِلَيْهَا فَأَعْجَبَهُ مَا رَأَى مِنْ ثَمَرِهَا ثُمَّ رَجَعَ إِلَى صَلاَتِهِ فَإِذَا هُوَ لاَ يَدْرِي كَمْ صَلَّى فَقَالَ لَقَدْ أَصَابَتْنِي فِي مَالِي هَذَا فِتْنَةٌ ‏.‏ فَجَاءَ عُثْمَانَ بْنَ عَفَّانَ - وَهُوَ يَوْمَئِذٍ خَلِيفَةٌ - فَذَكَرَ لَهُ ذَلِكَ وَقَالَ هُوَ صَدَقَةٌ فَاجْعَلْهُ فِي سُبُلِ الْخَيْرِ ‏.‏ فَبَاعَهُ عُثْمَانُ بْنُ عَفَّانَ بِخَمْسِينَ أَلْفًا فَسُمِّيَ ذَلِكَ الْمَالُ الْخَمْسِينَ ‏.‏