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
The most important sources of borrowings into (pre-Islamic) Arabic are from the related (Semitic) languages Aramaic, which used to be the principal, international language of communication throughout the ancient Near and Middle East, Ethiopic, and to a lesser degree Hebrew (mainly religious concepts). In addition, many cultural, religious and political terms have entered Arabic from Iranian languages, notably Middle Persian, Parthian, and (Classical) Persian, and Hellenistic Greek ("kīmiyāʼ" has as origin the Greek "khymia", meaning in that language the melting of metals; see Roger Dachez, "Histoire de la Médecine de l'Antiquité au XXe siècle", Tallandier, 2008, p. 251), "alembic" (distiller) from "ambix" (cup), "almanac" (climate) from "almenichiakon" (calendar). (For the origin of the last three borrowed words, see Alfred-Louis de Prémare, "Foundations of Islam", Seuil, L'Univers Historique, 2002.) Some Arabic borrowings from Semitic or Persian languages are, as presented in De Prémare's above-cited book: