I heard the Messenger of Allah ﷺ say, "A band of Muslims," or he said, "of the believers, will surely conquer the treasure of the house of Chosroes that lies in the White Palace."
حدثنا عفان حدثنا أبو عوانة عن سماك
سمعت رسول الله ﷺ يقول لتفتحن عصابة من المسلمين أو من المؤمنين كنز آل كسرى الذي في الأبيض
Its isnad is sahih. The first part of it appeared earlier at 20684, and the second part, that Allah named Madinah Taybah, was narrated by Bukhari in meaning, 4/88, no. 1872 Fath, and Muslim, 2/1007, no. 1385, with similar wording, and Tirmidhi, 5/239, no. 3028, who said, hasan sahih.