the seeker and Muhammad is established. It is through Muhammad that Sufis aim to learn about, understand and connect with God. Ali is regarded as one of the major figures amongst the Sahaba who have directly pledged allegiance to Muhammad, and Sufis maintain that through Ali, knowledge about Muhammad and a connection with Muhammad may be attained. Such a concept may be understood by the hadith, which Sufis regard to be authentic, in which Muhammad said, "I am the city of knowledge, and Ali is its gate." Eminent Sufis such as Ali Hujwiri refer to Ali as having a very high ranking in Tasawwuf. Furthermore, Junayd of Baghdad regarded Ali as Sheikh of the principals and practices of Tasawwuf. Historian Jonathan A.C. Brown notes that during the lifetime of Muhammad, some companions were more inclined than others to "intensive devotion, pious abstemiousness and pondering the divine mysteries" more than Islam required, such as Abu Dharr al-Ghifari. Hasan al-Basri, a tabi', is considered a "founding figure" in the "science of purifying the heart". Practitioners of Sufism hold that in its early stages of development Sufism effectively referred to nothing more than the internalization of Islam. According to one perspective, it is directly from the Qur'an, constantly recited, meditated, and experienced, that Sufism proceeded, in its origin and its development. Other practitioners have held that Sufism is the strict emulation of the way of Muhammad, through which the heart's connection to the Divine is strengthened. Some contend that Sufism developed from people like Bayazid Bastami, who, in his utmost reverence to the sunnah, refused to eat a watermelon because he did not find any proof that Muhammad ever ate it. According to the late medieval mystic, the Persian poet Jami, Abd-Allah ibn Muhammad ibn al-Hanafiyyah (died c. 716) was the first person to be called a "Sufi". The term also had a strong connection with Kufa, with three of the earliest scholars to be called by the term being Abu Hashim al-Kufi, Jabir ibn Hayyan and Abdak al-Sufi. Later individuals included Hatim al-Attar, from Basra, and Al-Junayd al-Baghdadi. Others, such as Al-Harith al-Muhasibi and Sari al-Saqati, were not known as Sufis during their lifetimes, but later came to be identified as such. Important contributions in writing are attributed to Uwais al-Qarani, Hasan of Basra, Harith al-Muhasibi, Abu Nasr as-Sarraj and Said ibn al-Musayyib. Ruwaym, from the second generation of Sufis in Baghdad,