Al-Kāfi
Hadith 916عِدَّةٌ مِنْ أَصْحَابِنَا عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ قَالَ كَتَبْتُ إِلَيْهِ ( عليه السلام ) جُعِلْتُ فِدَاكَ مِنْ كُلِّ سُوءٍ امْرَأَةٌ أَرْضَعَتْ عَنَاقاً حَتَّى فُطِمَتْ وَ كَبِرَتْ وَ ضَرَبَهَا الْفَحْلُ ثُمَّ وَضَعَتْ أَ يَجُوزُ أَنْ يُؤْكَلَ لَحْمُهَا وَ لَبَنُهَا فَكَتَبَ ( عليه السلام ) فِعْلٌ مَكْرُوهٌ وَ لَا بَأْسَ بِهِ .
4. A number of our people have narrated from Ahmad ibn Muhammad from who has said the following: “I once wrote to him (the Imam) (a.s.), saying, ‘I pray to Allah to keep my soul in service for your cause against all evil, a woman has breastfed a young she-goat and weaned it. It grew up and gave birth. Is it permissible to use its milk and flesh for food?’ He (the Imam) wrote back saying, ‘It is an undesirable act but it is not unlawful.’ ”