Hadith.838 - Yunus ibn Ya'qub said:
"I saw Imam Jafar ibn Muhammad Al-Sadiq (as) leveling the pebbles at the place of his prostration between the two prostrations."
Man Lā Yaḥḍuruh al-Faqīh #839"I saw Imam Jafar ibn Muhammad Al-Sadiq (as), every time he prostrated and then raised his head, he would take the pebbles from his forehead...