28-23 (The author of the book narrated) my father - may God be pleased with him - narrated that Sa’d ibn Abdullah quoted on the authority of Muhammad ibn Isa ibn Obayd, on the authority of Soleiman ibn Hafs al-Marwazi, “Abul Hassan (s) wrote me a letter in which he (s) wrote, Say ‘Thanks Thanks’ or ‘Forgive Forgive’ one hundred times when you perform the prostration for expression of your gratitude.”The author of this book (Sheikh Sadooq) said, “Soleiman ibn Hafs visited both Musa ibn Ja’far (s) and Al-Ridha (s) and I do not know from which of the two Imams (s) this tradition has been narrated on the authority of.”