What is meant by the two red and white treasures mentioned in the Hadith: "And I was given the two red and white treasures"?

Al-Nawawi said in his commentary on the Hadith (definition) of the two treasures: They are gold and silver, and what is meant by them are the treasures of Khosrau and Caesar, the kings of Iraq and Shaam. In this, there is an indication of the expansion of the dominion of the Islamic nation in the East and West, and that did indeed happen, whereas the expansion of their dominion in the North and South was limited compared to the East.