Answer
Shia Muslims highly regard Ali al-Sajjad, the fourth Shia Imam. He is known for his piety, knowledge, and eloquence. His supplications, collected in the book "Sahifa al-Sajjadiyya," are considered some of the most beautiful and profound in Islamic literature. Shia Muslims believe that Ali al-Sajjad was a direct descendant of the Prophet Muhammad and the rightful successor to his father, Imam Husayn.