Some translations prefer to set apart extended quotations, prayers or songs. The ULB and many other English translations indent the lines of this chapter, which is an extended quotation.
The first part of this chapter is probably a prophecy about the coming Messiah and not Isaiah because this was different than the message Isaiah delivered. (See: [[rc://en/tw/dict/bible/kt/christ]])
This chapter prophesies concerning a future time of peace and restoration. It is unlikely to have been fulfilled in Isaiah's day. (See: [[rc://en/tw/dict/bible/kt/restore]], [[rc://en/tw/dict/bible/kt/prophet]] and [[rc://en/tw/dict/bible/kt/fulfill]])