Hebrew University archaeologists have discovered an 8th century BCE seal impression in First Temple remains near Jerusalem’s Temple Mount. It is inscribed with the Hebrew letters that seem to spell out the name l’Yesha’yah[u] (belonging to Isaiah) and part of the word navi (prophet).

https://www.timesofisrael.com/in-find-of-biblical-proportions-proof-of-prophet-isaiah-believed-unearthed/