Jewish History: Biblical History: The Killing of Isaiah:
How was Isaiah killed?
The Talmud (Yevamos 49b) tells us that King Menasheh
accused Isaiah of sacrilege for claiming to have seen
G-d (Is.6:1). Isaiah tried to escape by hiding inside
a cedar tree, but he was detected (Yerushalmi Sanhedrin
10:2) and they sawed the cedar tree apart, killing him.
Ask a follow-up question