Caliph Al-Hasan ibn ‘Ali is the grandson of which Islamic prophet?
Mujtaba Al-Mujtaba (Arabic: اَلْـمُـجْـتَـبَى‎ ‎ ) is an Arabic word which means "The Selected One" or "The Chosen One among many." It is a title of the Islamic "Nabi" (Arabic: نَـبِي‎ ‎ , Prophet) Muhammad, and his grandson, the Caliph Al-Hasan ibn ‘Ali.
Kumayl ibn Ziyad Kumayl bin Ziyad an-Nakha'i (Arabic: كُميل بن زياد النخعي‎ ‎ ) was among the most loyal companions of Imam Ali Ibn Abi Talib. Moreover, Kumayl occupies a prominent position in Shia Islam. Converting to Islam during the time of Islamic prophet Muhammad, he rose to a position of prominence during the caliphates of Uthman and Ali. In the caliphate of Ali, Kumayl flourished and served him in the most disciplined of ways. However, he is recognized for his pious and humble nature as well as preserving Imam Ali's teachings. Kumayl is best known for the "du'a" (supplication) of Prophet Khidr, which is commonly known by the name "du'a Kumayl."