Background: Abu 'Abd ar-Rahman al-Khalil ibn Ahmad ibn 'Amr ibn Tammam al-Farahidi al-Azdi al-Yahmadi (Arabic: 'bw `bdlrHmn lkhlyl bn 'Hmd lfrhydy; 718 - 786 CE), known as Al-Farahidi, or simply Al-Khalil, famously compiled the first known dictionary of the Arabic language, and one of the first in any language, Kitab al-'Ayn (Arabic: ktb l`yn).. He was one of the earliest Arab lexicographer philologists, and is accredited for introducing the Harakat (vowel marks in Arabic script) system now in standard use, and the study of al-'arud (Arabic prosody), musicology and metre. His linguistic theories formed the basis for the development of prosody studies in the Persian, Turkish and Urdu languages.
Context: Al-Farahidi's eschewing of material wealth has been noted by a number of biographers. In his old age, the son of Habib ibn al-Muhallab and reigning governor of the Muhallabids offered al-Farahidi a pension and requested that the latter tutor the former's son. Al-Farahidi declined, stating that he was wealthy though possessing no money, as true poverty lay not in a lack of money, but in the soul. The governor reacted by rescinding the pension, an act to which al-Farahidi responded with the following lines of poetry: "He, Who formed me with a mouth, engaged to give me nourishment till such a time as He takes me to Himself. Thou hast refused me a trifling sum, but that refusal will not increase thy wealth." Embarrassed, the governor then responded with an offer to renew the pension and double the rate, which al-Farahidi still greeted with a lukewarm reception. Al-Farahidi's apathy about material wealth was demonstrated in his habit of quoting Akhtal's famous stanza: "If thou wantest treasures, thou wilt find none equal to a virtuous conduct." Al-Farahidi distinguished himself via his philosophical views as well. He reasoned that a man's intelligence peaked at the age of forty - the age when the Islamic prophet Muhammad began his call - and began to diminuish after sixty, the point at which Muhammad died. He also believed that a person was at their peak intelligence at the clearest part of dawn. In regard to the field of grammar, al-Farahidi held the realist views common among early Arab linguists yet rare among both later and modern times. Rather than holding the rules of grammar as he and his students described them to be absolute rules, al-Farahidi saw the Arabic language as the natural, instinctual speaking habits of the Bedouin; if the descriptions of scholars such as himself differed from how the Arabs of the desert naturally spoke, then the cause was a lack of knowledge on the scholar's part as the unspoken, unwritten natural speech of pure Arabs was the final determiner. Al-Farahidi was distinguished, however, in his view that the Arabic alphabet included 29 letters rather than 28 and that each letter represented a fundamental characteristic of people or animals. His classification of 29 letters was due to his consideration of the combination of Lamedh and Aleph as a separate third letter from the two individual parts. CANNOTANSWER
Question: What other views did he have?. Whats the answer?

He reasoned that a man's intelligence peaked at the age of forty - the age when the Islamic prophet Muhammad began