Chapter on the Ruling Regarding Reserved Areas
Man Lā Yaḥḍuruh al-Faqīh|Volume 3|Book 1|Chapter 42
وَ قَالَ عَلَيْهِ اَلسَّلاَمُ: "يَكُونُ بَيْنَ اَلْبِئْرَيْنِ إِنْ كَانَتْ أَرْضاً صُلْبَةً خَمْسُمِائَةِ ذِرَاعٍ وَ إِنْ كَانَتْ رِخْوَةً فَأَلْفُ ذِرَاعٍ ".
Imam عليه السلام said: "There should be a distance of five hundred cubits between two wells if the land is solid, and one thousand cubits if the land is loose."
- Ṣaḥīḥ al-Faqīh