10. My father narrated to me from Sa’d, from ‘Ali ibn Ismā’īl ibn ‘Isā, from Safwān ibn Yaḥyā, from ‘Ǐs ibn Qāsim, who said: I asked Abā ‘Abdillāh (Imam Sādiq ), “Is there an obligatory prayer which should be established after the Ziyārah of the Grave (of Ḥusain )?” Imam replied, “There are no obligatory prayers for Ziyārah.” I asked, “How frequently should I go to his Ziyārah?” Imam replied, “As frequently as you wish.”