The Funeral Prayer (Salat Al-Janazah)
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 26
وَقَالَ اَلصَّادِقُ عَلَيْهِ اَلسَّلاَمُ: «حَدُّ اَلْقَبْرِ إِلَى اَلتَّرْقُوَةِ»
Imam Jafar ibn Muhammad Al-Sadiq عليه السلام said: "The depth of the grave is to the collarbone (clavicle)."
- Ṣaḥīḥ al-Faqīh