What is the origin of Arabs?

The Arabs are divided into Northern Arabs (Hijazis) and Southern Arabs (Yamanis). The Northern Arabs trace their lineage back to Ismail ibn Ibrahim, peace be upon them both, and are divided into Rabi'a and Mudar, which includes Quraish. The Southern Arabs are descendants of Qahtan and are divided into Kahlan and Himyar. Allah chose the Arabs from among the children of Adam, and from the Arabs He chose Quraish, and from Quraish Bani Hashim, and He chose Prophet Muhammad, peace be upon him, from Bani Hashim. The Arabs lived in a state of ignorance (Jahiliyyah) before Islam, then Allah honored them with the advent of Prophet Muhammad, peace be upon him.