Joseph’s brothers sold him either to Ishmaelites or to Midianites—both versions are found in Genesis 37. Supposedly the Yahwist source had Ishmaelites and the Elohist source had Midianites. Ishmael and Midian were both sons of Abraham by different women. I don’t think they are explicitly called Arabs but haven’t made a search.
The Arab lifestyle and social structure pre-dates Abraham and the Bronze Age. But Ishmael’s descendants eventually came to it, and that’s reflected in the duality of Arab society. The Qys Arabs do not intermarry with the Yemen Arabs, who maintain that they were the first, and that the Qys Arabs are Ishmaelites-come-latelys. Off and on over the centuries they have been sabotaging each others’ agriculture and feuding. Mohammed with a Qys Arab. This dychotomy has been significantly reduced since Israel reemerged for them both to hate.