Sunan Ibn Majah, Volume 3, Book 8, Hadith 1805 (DarusSalam) ⓘ
It was narrated from Ibn Shihab, from Salim bin Abdullah, from his father, from the Messenger of Allah: Salim said: “My father read to me a letter that the Messenger of Allah had written about Sadaqat before Allah caused him to pass away. I read in it: 'For forty sheep, one sheep, up to one hundred and twenty. If there is more than that - even one - then two sheep, up to two hundred, If there is one more than that - even one = then three sheep, up to three hundred. If there are many sheep, then for each hundred, one sheep.' And I read in it: 'Separate flocks should not be combined, and a combined flock should not be separated.' And I read in it: 'And a male goat should not be taken for Sadaqah, nor a decrepit nor defective animal.' ”
حَدَّثَنَا بَكْرُ بْنُ خَلَفٍ، حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ مَهْدِيٍّ، حَدَّثَنَا سُلَيْمَانُ بْنُ كَثِيرٍ، حَدَّثَنَا ابْنُ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، عَنْ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ أَقْرَأَنِي سَالِمٌ كِتَابًا كَتَبَهُ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ فِي الصَّدَقَاتِ قَبْلَ أَنْ يَتَوَفَّاهُ اللَّهُ فَوَجَدْتُ فِيهِ " فِي أَرْبَعِينَ شَاةً شَاةٌ إِلَى عِشْرِينَ وَمِائَةٍ فَإِذَا زَادَتْ وَاحِدَةً فَفِيهَا شَاتَانِ إِلَى مِائَتَيْنِ فَإِذَا زَادَتْ وَاحِدَةً فَفِيهَا ثَلاَثُ شِيَاهٍ إِلَى ثَلاَثِمِائَةٍ فَإِذَا كَثُرَتْ فَفِي كُلِّ مِائَةٍ شَاةٌ " . وَوَجَدْتُ فِيهِ " لاَ يُجْمَعُ بَيْنَ مَتَفَرِّقٍ وَلاَ يُفَرَّقُ بَيْنَ مُجْتَمِعٍ " . وَوَجَدْتُ فِيهِ " لاَ يُؤْخَذُ فِي الصَّدَقَةِ تَيْسٌ وَلاَ هَرِمَةٌ وَلاَ ذَاتُ عَوَارٍ " .
also referenced under: Hadith 1805 (Reference) & Book 8, Hadith 23 (In-Book)