Al-Khalil Ibn Ahmad was an influential Arab scholar and linguist born in the 8th century in Oman. He is best known for his pioneering work in Arabic lexicography and phonetics. His most notable contribution is the creation of the first Arabic dictionary, called Kitab al-Ayn, which organized words based on their phonetic roots. In addition to his work in linguistics, Al-Khalil was also a prominent poet and a key figure in the development of Arabic prosody. He established the rules of meter in Arabic poetry, which greatly influenced subsequent generations of poets and scholars. His contributions laid the foundation for the study of the Arabic language.