Sahih al-Bukhari 6955Book 90, Hadith 3
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الأَنْصَارِيُّ، حَدَّثَنَا أَبِي، حَدَّثَنَا ثُمَامَةُ بْنُ عَبْدِ اللَّهِ بْنِ أَنَسٍ، أَنَّ أَنَسًا، حَدَّثَهُ أَنَّ أَبَا بَكْرٍ كَتَبَ لَهُ فَرِيضَةَ الصَّدَقَةِ الَّتِي فَرَضَ رَسُولُ اللَّهِ صلى الله عليه وسلم " وَلاَ يُجْمَعُ بَيْنَ مُتَفَرِّقٍ وَلاَ يُفَرَّقُ بَيْنَ مُجْتَمِعٍ خَشْيَةَ الصَّدَقَةِ ".
That Abu Bakr wrote for him, Zakat regulations which Allah's Messenger (ﷺ) had made compulsory, and wrote that one should neither collect various portions (of the property) nor divide the property into various portions in order to avoid paying Zakat.