there was very little in the way of an "Arab" self-conscious identity before Islam, which is also what pre-Islamic sources sometimes imply: there, terms related to "Arab" have a very long history but they apprear almost exclusively used to define people of central Arabia by outsiders, and often not very proximate ones; this is puzzling, because we have tons of written matierial from Arabia by its inhabitants wihtout any hint at all that they, or a subgroup of them, called themselves "Arabs", while we have a likewise fairly strong and varied array of sources calling them like that. In Late Antiquity, there's a reversal: "Arabs" is rarely if at all used by contemporary non-Arab sources, while it appears very sporadically in sources from the Arabs themselves, who seem to have begun to use the label massively only some decades into the Islamic period
It that explicitly tied to Islam or more to the sudden presence of Arabs as a ruling/military class in the Near East