Isolated nomads progressively spread southwards and reached South Arabia, where the South Arabian language was spoken. They established linguistic contacts back and forth between Syria and South Arabia and their languages. That is why Garbini considers that Arabic does not belong exclusively to either the Northwest Semitic languages (Aramaic, Phoenician, Hebrew, etc.)
Remote tribes gradually expanded southward and arrived at South Arabia, where the South Arabian language was spoken. They had linguistic exchanges between Syria and South Arabia as well as their languages. This is why Garbini believes that Arabic does not exclusively belong to either the Northwest Semitic languages (Aramaic, Phoenician, Hebrew, etc.).