Tuesday
“The signs of a true believer are five: (1) offering a fifty-one rakāt of daily obligatory and supererogatory prayers, (2) visiting the tomb of Imam al-Husayn on the twentieth of Safar (i.e. Ziyarat al-Arba’in), (3) putting a ring in the right hand, (4) putting one’s forehead on earth (i.e. prostrating oneself to Almighty Allah earnestly), and (5) repeating the Basmalah (بِسْمِ ٱللهِ ٱلرَّحْمٰنِ ٱلرَّحِيمِ Bismi Llāhi r-Raḥmāni r-Raḥīmi: In the Name of Allah, the All-beneficent, the All-merciful) loudly in certain prayers.
In Tahdhib al-Ahkam and al-Misbah, Shaykh al-Tusi has mentioned a form of Ziyarah that is dedicated to this day.