Chapter on Virtues of Hajj
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 2
وَ قَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: «أَسَاسُ اَلْبَيْتِ مِنَ اَلْأَرْضِ اَلسَّابِعَةِ اَلسُّفْلَى إِلَى اَلْأَرْضِ اَلسَّابِعَةِ اَلْعُلْيَا».
Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said: "The foundation of the House (Kaaba) extends from the seventh layer of the lower earth to the seventh layer of the upper earth."
- Ṣaḥīḥ al-Faqīh