The Messenger of Allah ﷺ said, "You will fight the Arabian Peninsula and Allah will grant you victory over it. Then you will fight Persia and Allah will grant you victory over them. Then you will fight the Romans and Allah will grant you victory over them. Then you will fight the Dajjal and Allah will grant you victory over him."
حدثنا يزيد أخبرنا المسعودي عن عبد الملك بن عمير عن جابر بن سمرة
قال رسول الله ﷺ تقاتلون جزيرة العرب فيفتحها الله وتقاتلون فارس فيفتحهم الله وتقاتلون الروم فيفتحهم الله وتقاتلون الدجال فيفتحه الله
Its isnad is sahih, its narrators being well known reliable men. Jabir bin Samura was a companion, and the hadith was narrated by Ibn Majah, 2/1370, no. 4091, in "Fitan." Hakim graded it sahih, 4/426, and Dhahabi agreed with him.