[Machine] The Prophet ﷺ wrote to the people of Yemen, saying: "Every thirty camels for sale should have a male or female calf, and every forty camels for sale should have a cow." Abu Abdul Rahman Al-Sulami narrated from Abu Amr bin Hamdan, who narrated from Abdullah bin Muhammad bin Abdul Aziz, who narrated from Al-Hakam bin Musa, who narrated from Yahya bin Hamza, who narrated from Sulaiman bin Dawood, who mentioned it.  

عَنِ النَّبِيِّ ﷺ أَنَّهُ كَتَبَ إِلَى أَهْلِ الْيَمَنِ قَالَ فِيهِ وَفِي كُلِّ ثَلَاثِينَ بَاقُورَةً تَبِيعٌ جَذَعٌ أَوْ جَذَعَةٌ وَفِي كُلِّ أَرْبَعِينَ بَاقُورَةً بَقَرَةٌ حَدَّثَنِيهِ أَبُو عَبْدِ الرَّحْمَنِ السُّلَمِيُّ أنبأ أَبُو عَمْرِو بْنُ حَمْدَانَ أنبأ عَبْدُ اللهِ بْنُ مُحَمَّدِ بْنِ عَبْدِ الْعَزِيزِ ثنا الْحَكَمُ بْنُ مُوسَى ثنا يَحْيَى بْنُ حَمْزَةَ عَنْ سُلَيْمَانَ بْنِ دَاوُدَ فَذَكَرَهُ