Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
nasai-kubra:4430 – ʿAmr b. Yaḥyá > Maḥbūb > Abū Isḥāq > Mūsá b. Abū ʿĀʾishah > Saʾalt Yaḥyá b. al-Jazzār > Hadhih al-Āyah Wāʿlamūā Annamā Ghanimtum from Shayʾ Faʾan Lillah Khumusah al-Nfāl 41

[Machine] I asked, "How much of the fifth portion did the Prophet ﷺ have?" He replied, "One-fifth of the fifth portion."  

الكبرى للنسائي:٤٤٣٠ – أَخْبَرَنَا عَمْرُو بْنُ يَحْيَى قَالَ حَدَّثَنَا مَحْبُوبٌ قَالَ أَخْبَرَنَا أَبُو إِسْحَاقَ عَنْ مُوسَى بْنِ أَبِي عَائِشَةَ قَالَ سَأَلْتُ يَحْيَى بْنَ الْجَزَّارِ عَنْ هَذِهِ الْآيَةِ {§وَاعْلَمُوا أَنَّمَا غَنِمْتُمْ مِنْ شَيْءٍ فَأَنَّ لِلَّهِ خُمُسَهُ} [الأنفال 41] قَالَ

قُلْتُ كَمْ كَانَ لِلنَّبِيِّ ﷺ مِنَ الْخُمُسِ؟ قَالَ «خُمُسُ الْخُمُسِ»  

See similar narrations below:

Collected by Bayhaqī
bayhaqi:12940 – Abū al-Ḥasan ʿAlī b. Muḥammad al-Muqriʾ > al-Ḥasan b. Muḥammad b. Isḥāq > Yūsuf b. Yaʿqūb > Abū al-Rabīʿ > Jarīr > Mūsá b. Abū ʿĀʾishah

[Machine] I asked Yahya bin Al-Jazzar, "How much did the Messenger of Allah ﷺ take as Khums?" He replied, "He took one-fifth of the fifth."  

البيهقي:١٢٩٤٠ – وَأَخْبَرَنَا أَبُو الْحَسَنِ عَلِيُّ بْنُ مُحَمَّدٍ الْمُقْرِئُ أنا الْحَسَنُ بْنُ مُحَمَّدِ بْنِ إِسْحَاقَ ثنا يُوسُفُ بْنُ يَعْقُوبَ ثنا أَبُو الرَّبِيعِ ثنا جَرِيرٌ عَنْ مُوسَى بْنِ أَبِي عَائِشَةَ قَالَ

سَأَلْتُ يَحْيَى بْنَ الْجَزَّارِ قُلْتُ كَمْ لِرَسُولِ اللهِ ﷺ مِنَ الْخُمُسِ؟ قَالَ خُمُسُ الْخُمُسِ