Sunan an-Nasa'i 2455
It was narrated from Anas bin Malik that Abu Bakar, may Allah be pleased with him, wrote to him:
"This is the obligation of Sadaqah which  the Messenger of Allah enjoined upon the Muslims, as Allah commanded the Messenger of Allah Whoever is asked for it in the manner explained (in the letter of Abu Bakar), let him give it, and whoever is asked for more than that, let him not give it. When there are less than twenty-five camels, for every five camels, one sheep (is to be given). If the number reaches twenty-five, then a Bint Makhad (a one-year-old she-camel) is due, up to thirty-five. If a Bint Makhad (a one-year-old male camel). If the number reaches thirty-six, then a Bint Labun (a two-year-old she-camel) is due, up to forty five. If the number reaches forty-six, then a Hiqqah (a three year old she-camel) that was bred by a stallion camel is due, up to sixty. If the number reaches sixty-one, then a Jadh'ah (a four-year-old she-camel) is due, up to seventy-five. If the number reaches seventy-six, then two Bint Labun are due, up to ninety. If the number reaches ninety-one, then two Hiqqahs that have been bred by stallion camels are due, up to one hundred and twenty. If there are more than one hundred and twenty, then for every forty a Bint Labun and for every fifty a Hiqqah. In the event that a person does not have a camel of the age specified according to the Sadaqah regulation, then if a person owes a Jadh'ah but he has a Hiqqah, then the Hiqqah should be accepted from him and he should give two sheep along with it if they are available, or twenty Dirhams. If a person owes a Hiqqah as Sadaqah but he only has a Jadh'ah, then it shold be accepted from him, and the Zakah collector should give him twenty Dirhams or two sheep. If a person owes a Hiqqah and does not have one but he has a Bint Labun, it should be accepted from him, and he should give two sheep along with it, if they are available, or twenty Dirhams. If a person owes a Bint Labun as Sadaqah but he only has a Hiqqah, it should be accepted from him, and the Zakah collector should give him twenty Dirhams or two sheep. If a person owes a Bint Labun as Sadaqah and he does not have a Bint Labun, but he has a Bint Makhad. It should be accepted from him, and he should give two sheep along with it, if they are available, or twenty Dirhams. If a person owes a Bint Makhad as Sadaqah but he only has a Bint Labun, a male, it shold be accepted from him and nothing else (need be given) with it. If a person has only four camels, then nothing is due on them, unless their owner wishes (to give something). With regard to the Sadaqah of grazing sheep, if there are forty then one sheep is due, up to one hundred and twenty. If there is one more than that, then two sheep are due, up to two hundred. If there is one more than that, then three sheep are due, up to three hundred. If there is one more than that, then for every hundred one sheep is due, and no decrepit or defecting sheep or male sheep should be taken as Sadaqah unless the Zakah collector wishes. Do not combine separate flocks or separate combined flocks for fear of Sadaqah, Each partner (who has a share in a combined flock) shold pay Sadaqah in proportion to his shares. If a man's flock is one less than forty sheep, then nothing is due from them unless their owner wishes. With regard to silver, one-quarter of one-tenth, and if there are only one hundred and ninety, nothing is due unless the owner wishes."
أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ فَضَالَةَ بْنِ إِبْرَاهِيمَ النَّسَائِيُّ، قَالَ أَنْبَأَنَا شُرَيْحُ بْنُ النُّعْمَانِ، قَالَ حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ، عَنْ ثُمَامَةَ بْنِ عَبْدِ اللَّهِ بْنِ أَنَسِ بْنِ مَالِكٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، أَنَّ أَبَا بَكْرٍ، رضى الله عنه كَتَبَ لَهُ أَنَّ هَذِهِ فَرَائِضُ الصَّدَقَةِ الَّتِي فَرَضَ رَسُولُ اللَّهِ صلى الله عليه وسلم عَلَى الْمُسْلِمِينَ الَّتِي أَمَرَ اللَّهُ بِهَا رَسُولَهُ صلى الله عليه وسلم فَمَنْ سُئِلَهَا مِنَ الْمُسْلِمِينَ عَلَى وَجْهِهَا فَلْيُعْطِهَا وَمَنْ سُئِلَ فَوْقَهَا فَلاَ يُعْطِهِ فِيمَا دُونَ خَمْسٍ وَعِشْرِينَ مِنَ الإِبِلِ فِي خَمْسِ ذَوْدٍ شَاةٌ فَإِذَا بَلَغَتْ خَمْسًا وَعِشْرِينَ فَفِيهَا بِنْتُ مَخَاضٍ إِلَى خَمْسٍ وَثَلاَثِينَ فَإِنْ لَمْ تَكُنِ ابْنَةُ مَخَاضٍ فَابْنُ لَبُونٍ ذَكَرٌ فَإِذَا بَلَغَتْ سِتَّةً وَثَلاَثِينَ فَفِيهَا بِنْتُ لَبُونِ إِلَى خَمْسٍ وَأَرْبَعِينَ فَإِذَا بَلَغَتْ سِتَّةً وَأَرْبَعِينَ فَفِيهَا حِقَّةٌ طَرُوقَةُ الْفَحْلِ إِلَى سِتِّينَ فَإِذَا بَلَغَتْ إِحْدَى وَسِتِّينَ فَفِيهَا جَذَعَةٌ إِلَى خَمْسَةٍ وَسَبْعِينَ فَإِذَا بَلَغَتْ سِتَّةً وَسَبْعِينَ فَفِيهَا ابْنَتَا لَبُونٍ إِلَى تِسْعِينَ فَإِذَا بَلَغَتْ إِحْدَى وَتِسْعِينَ فَفِيهَا حِقَّتَانِ طَرُوقَتَا الْفَحْلِ إِلَى عِشْرِينَ وَمِائَةٍ فَإِذَا زَادَتْ عَلَى عِشْرِينَ وَمِائَةٍ فَفِي كُلِّ أَرْبَعِينَ ابْنَةُ لَبُونٍ وَفِي كُلِّ خَمْسِينَ حِقَّةٌ فَإِذَا تَبَايَنَ أَسْنَانُ الإِبِلِ فِي فَرَائِضِ الصَّدَقَاتِ فَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ الْجَذَعَةِ وَلَيْسَتْ عِنْدَهُ جَذَعَةٌ وَعِنْدَهُ حِقَّةٌ فَإِنَّهَا تُقْبَلُ مِنْهُ الْحِقَّةُ وَيَجْعَلُ مَعَهَا شَاتَيْنِ إِنِ اسْتَيْسَرَتَا لَهُ أَوْ عِشْرِينَ دِرْهَمًا وَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ الْحِقَّةِ وَلَيْسَتْ عِنْدَهُ إِلاَّ جَذَعَةٌ فَإِنَّهَا تُقْبَلُ مِنْهُ وَيُعْطِيهِ الْمُصَّدِّقُ عِشْرِينَ دِرْهَمًا أَوْ شَاتَيْنِ وَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ الْحِقَّةِ وَلَيْسَتْ عِنْدَهُ وَعِنْدَهُ ابْنَةُ لَبُونٍ فَإِنَّهَا تُقْبَلُ مِنْهُ وَيَجْعَلُ مَعَهَا شَاتَيْنِ إِنِ اسْتَيْسَرَتَا لَهُ أَوْ عِشْرِينَ دِرْهَمًا وَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ بِنْتِ لَبُونٍ وَلَيْسَتْ عِنْدَهُ إِلاَّ حِقَّةٌ فَإِنَّهَا تُقْبَلُ مِنْهُ وَيُعْطِيهِ الْمُصَّدِّقُ عِشْرِينَ دِرْهَمًا أَوْ شَاتَيْنِ وَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ بِنْتِ لَبُونٍ وَعِنْدَهُ بِنْتُ مَخَاضٍ فَإِنَّهَا تُقْبَلُ مِنْهُ وَيَجْعَلُ مَعَهَا شَاتَيْنِ إِنِ اسْتَيْسَرَتَا لَهُ أَوْ عِشْرِينَ دِرْهَمًا وَمَنْ بَلَغَتْ عِنْدَهُ صَدَقَةُ ابْنَةِ مَخَاضٍ وَلَيْسَتْ عِنْدَهُ إِلاَّ ابْنُ لَبُونٍ ذَكَرٌ فَإِنَّهُ يُقْبَلُ مِنْهُ وَلَيْسَ مَعَهُ شَىْءٌ وَمَنْ لَمْ يَكُنْ عِنْدَهُ إِلاَّ أَرْبَعَةٌ مِنَ الإِبِلِ فَلَيْسَ فِيهَا شَىْءٌ إِلاَّ أَنْ يَشَاءَ رَبُّهَا وَفِي صَدَقَةِ الْغَنَمِ فِي سَائِمَتِهَا إِذَا كَانَتْ أَرْبَعِينَ فَفِيهَا شَاةٌ إِلَى عِشْرِينَ وَمِائَةٍ فَإِذَا زَادَتْ وَاحِدَةٌ فَفِيهَا شَاتَانِ إِلَى مِائَتَيْنِ فَإِذَا زَادَتْ وَاحِدَةٌ فَفِيهَا ثَلاَثُ شِيَاهٍ إِلَى ثَلاَثِمِائَةٍ فَإِذَا زَادَتْ وَاحِدَةٌ فَفِي كُلِّ مِائَةٍ شَاةٌ وَلاَ تُؤْخَذُ فِي الصَّدَقَةِ هَرِمَةٌ وَلاَ ذَاتُ عَوَارٍ وَلاَ تَيْسُ الْغَنَمِ إِلاَّ أَنْ يَشَاءَ الْمُصَّدِّقُ وَلاَ يُجْمَعُ بَيْنَ مُتَفَرِّقٍ وَلاَ يُفَرَّقُ بَيْنَ مُجْتَمِعٍ خَشْيَةَ الصَّدَقَةِ وَمَا كَانَ مِنْ خَلِيطَيْنِ فَإِنَّهُمَا يَتَرَاجَعَانِ بَيْنَهُمَا بِالسَّوِيَّةِ وَإِذَا كَانَتْ سَائِمَةُ الرَّجُلِ نَاقِصَةً مِنْ أَرْبَعِينَ شَاةٌ وَاحِدَةٌ فَلَيْسَ فِيهَا شَىْءٌ إِلاَّ أَنْ يَشَاءَ رَبُّهَا وَفِي الرِّقَةِ رُبُعُ الْعُشْرِ فَإِنْ لَمْ يَكُنِ الْمَالُ إِلاَّ تِسْعِينَ وَمِائَةً فَلَيْسَ فِيهِ شَىْءٌ إِلاَّ أَنْ يَشَاءَ رَبُّهَا ‏.‏