Andrzej Sapkowski said this quote
“ Then the prophetess said to the witcher: I shall give you this advice: wear boots made of iron, takein hand a staff of steel. Then walk until the end of the world. Help yourself with your staff to break the land before you and wet it with your tears. Go through fire and water, do not stop along the way,do not look behind you. And when the boots are worn, when your staff is blunt, once the wind and the heat has dried your eyes so that your tears no longer flow, then at the end of the world you mayfind what you are looking for and what you love...The witcher went through fire and water, he did not look back. He did not take iron boots or a staffof steel. He took only his sword. He did not listen to the words of prophets. And he did well because she was a bad prophet. ”