Al-Kāfi - Volume 4 > The Case of One Who Throws Pebbles Improperly, or Throws Less or More
Hadith #4

محمد بن يحيى، عن أحمد بن محمد، عن علي بن الحكم، عن علي بن أبي حمزة، عن أبي بصير قال: قلت لابي عبدالله عليه السلام: ذهبت أرمي فإذا في يدي ست حصيات فقال: خذ واحدة من تحت رجلك.

4. Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad from Ali ibn al-Hakam from Ali ibn abu Hamzah from abu Basir who has said the following: “I once said to abu ‘Abd Allah, ‘Alayhi al-Salam, ‘I went to throw pebbles but there were only six pebbles in my hand.’ He (the Imam) said, ’Take one from under your feet.’”