One-fifth of Booty to the Cause of Allah (Khumus)
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا يَحْيَى، عَنْ سُفْيَانَ، قَالَ حَدَّثَنِي أَبُو إِسْحَاقَ، قَالَ سَمِعْتُ عَمْرَو بْنَ الْحَارِثِ، قَالَ مَا تَرَكَ النَّبِيُّ صلى الله عليه وسلم إِلاَّ سِلاَحَهُ وَبَغْلَتَهُ الْبَيْضَاءَ، وَأَرْضًا تَرَكَهَا صَدَقَةً.Narrated `Amr bin Al-Harith:The Prophet (ﷺ) did not leave anything (after his death) except his arms, a white mule, and a (piece of) land which he had given as Sadaqa
From Sahih al-Bukhari, whose reports the scholars accept as authentic.