Al-Kāfi - Volume 6 > Mixing of Lawful Things with others in Something
Hadith #2

عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنْ إِسْمَاعِيلَ بْنِ مَرَّارٍ عَنْ يُونُسَ عَنْهُمْ ( عليهم السلام ) قَالَ سُئِلَ عَنْ حِنْطَةٍ مَجْمُوعَةٍ ذَابَ عَلَيْهَا شَحْمُ الْخِنْزِيرِ قَالَ إِنْ قَدَرُوا عَلَى غَسْلِهَا أُكِلَتْ وَ إِنْ لَمْ يَقْدِرُوا عَلَى غَسْلِهَا لَمْ تُؤْكَلْ وَ قِيلَ تُبْذَرُ حَتَّى تَنْبُتَ .

2. Ali ibn Ibrahim has narrated from his father from ’Isma‘il ibn Marrar from Yunus from ‘A’immah, ‘Alayhim al-Salam, who have said the following: A’immah , ‘Alayhim al-Salam, were asked about a certain amount of wheat on which the fat of pigs has melted. He (the Imam) said, ‘If they can wash it they must do so and use it for food;but if they cannot wash it then they can use it as seed to grow a plantation. 5 ”