Numerical digit
From India, the thriving trade between Islamic sultans and Africa carried the concept to Cairo. Arabic mathematicians extended the system to include decimal fractions, and Muḥammad ibn Mūsā al-Ḵwārizmī wrote an important work about it in the 9th  century. The modern Arabic numerals were introduced to Europe with the translation of this work in the 12th century in Spain and Leonardo of Pisa's "Liber Abaci" of 1201. In Europe, the complete Indian system with the zero was derived from the Arabs in the 12th century.
Classical Arabic
The A1 inscription dated to the 3rd or 4th c. AD in the Greek alphabet in a dialect showing affinities to that of the Safaitic inscriptions shows that short final high vowels had been lost in at least some dialects of Old Arabic at that time, obliterating the distinction between nominative and genitive case in the singular, leaving the accusative the only marked case: