Mujtaba (title)
Mujtabā (Arabic: المُجتَبى), meaning the chosen one, is one of Imam Hasan's (a) titles. This title has also been used for the Prophet (s) and other Imams (a). In a sermon narrated from Imam al-Sadiq (a) describing the attributes of the Imams (a), this title is mentioned as an attribute of an Imam (a). However, it became particularly well-known in reference to Imam al-Hasan (a). In hadiths narrated from Imams of Shia, they have referred to Imam al-Hasan (a) with the title Mujtaba. The title "al-Mujtaba" is also mentioned in Tawassul supplication, and in the Hirz of Imam al-Sajjad (a), the phrase "al-Hasan al-Mujtaba" appears.
Mujtaba means the chosen one or the selected one. Allama Tabataba'i, in his interpretation of verse 121 of Quran 16, explains the word "ijtaba" by stating that God has purified the infallible Imams (a) for Himself in such a way that He distances them from deviance and guides them on the straight path.
It has been said that although this title has a special meaning that applies to all Imams of the Shi'a (a), only the second Imam of the Shi'a became famous by this title, and this indicates that the title "Mujtaba" was attributed to Imam al-Hasan (a) during his lifetime.