What is meant by the words of the Messenger of Allah, peace and blessings be upon him: "Expel the polytheists from the Arabian Peninsula, and permit delegations as I used to permit them"?

The polytheists are the disbelievers from among the idolaters and the People of the Book. The Arabian Peninsula specifically refers to the Hijaz (Mecca, Medina, Yamama, and their environs), and it is the region from which polytheists are forbidden to reside. The delegations are guests of Islam, and it is obligatory to permit them entry, honor them, and present them with gifts, whether they are Muslims or disbelievers. The third issue about which the narrator remained silent is said to be either the preparation of Usama's army or the prohibition against taking his grave as an idol.