In one narration the words are: "They will have a covenant of protection (dhimmah)." What the Prophet (peace and blessings be upon him) meant was that the mother of Sayyiduna Isma'il (peace be upon him) was from them.
Al-Tabarani recorded it with two chains, and the narrators of one of them are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 16680
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير “ (62/19)»