Al-Kāfi - Volume 3 > A Well near a Cesspool
Hadith #3

3ـ مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ مُحَمَّدِ بْنِ إِسْمَاعِيلَ عَنْ أَبِي إِسْمَاعِيلَ السَّرَّاجِ عَبْدِ الله بْنِ عُثْمَانَ عَنْ قُدَامَةَ بْنِ أَبِي يَزِيدَ الْحَمَّارِ عَنْ بَعْضِ أَصْحَابِنَا عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) قَالَ سَأَلْتُهُ كَمْ أَدْنَى مَا يَكُونُ بَيْنَ الْبِئْرِ بِئْرِ الْمَاءِ وَالْبَالُوعَةِ فَقَالَ إِنْ كَانَ سَهْلاً فَسَبْعَةُ أَذْرُعٍ وَإِنْ كَانَ جَبَلاً فَخَمْسَةُ أَذْرُعٍ ثُمَّ قَالَ الْمَاءُ يَجْرِي إِلَى الْقِبْلَةِ إِلَى يَمِينٍ وَيَجْرِي عَنْ يَمِينِ الْقِبْلَةِ إِلَى يَسَارِ الْقِبْلَةِ وَيَجْرِي عَنْ يَسَارِ الْقِبْلَةِ إِلَى يَمِينِ الْقِبْلَةِ وَلاَ يَجْرِي مِنَ الْقِبْلَةِ إِلَى دُبُرِ الْقِبْلَةِ.

3. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Muhammad ibn ’Isma‘il from abu ’Isma‘il from al-Sarraj from ‘Abd Allah ibn ‘Uthman from Qudamah ibn abu Yazid al-Hammar from certain persons of our people who have said the following: “I once asked abu ‘Abd Allah, ‘Alayhi al-Salam, about the distance needed between a well and a cesspool. He (the Imam) replied, ‘If the ground is plain, the distance must be seven yards; and if it is a hillside the distance must be five yards.’ He (the Imam) then said, ‘Water flows forward in direction, to the right or to the left or from its left side to its right side (in) forward direction but it does not flow backward.’”