The Rurf and the Vip Sweets

In tiddmadi the Prophet salallahu alayhi wa sallam said that in jannah there shall be rurf. There's going to be beautiful palaces multi-level layered multi-leveled built upon each other and the one inside can see outside and the one outside can see inside now we all can visualize this because we have seen structures built out of wall-to-wall ceiling and glass and whatnot right but when this hadith was said there was no such thing as see-through glass right? We also learn another very interesting thing about the rurf and that is hadith is in Tiddmadi, surat al-for Khan at