Semitic languages
The similarity of the Hebrew, Arabic and Aramaic languages was accepted by Jewish and Islamic scholars since medieval times. The languages were familiar to Western European scholars due to historical contact with neighbouring Near Eastern countries and through Biblical studies, and a comparative analysis of Hebrew, Arabic, and Aramaic was published in Latin in 1538 by Guillaume Postel. Almost two centuries later, Hiob Ludolf described the similarities between these three languages and the Ethiopian Semitic languages. However, neither scholar named this grouping as "Semitic".
Arabic definite article
The Arabic word "hādhā" is equivalent to the Hebrew word זה "zé". It appears that over time Hebrew shortened the demonstrative pronoun hazé ("eikh korím layéled hazé?" or What's this boy's name?) to simply "zé". That indicates that the Hebrew "ha-" was the accurate retention of the original proto-Semitic source, as opposed to "al-", which cannot conclusively be linked to the ancient cognate demonstrative pronoun "hādhā/hazé".