burnt offerings and sacrifices: In the past, God rejected Israel’s offerings when the people were living sinful lives (Isaiah 1:11–13). Their worship did not please him because their hearts were not right.
But God would accept offerings from righteous gentiles, that is, people from other nations who truly follow him. Being part of a certain nation does not matter if a person does not truly honor God.
a house of prayer for all the nations: The Lord would open the temple to all nations (see Isaiah 2:2–4). Jesus criticized the people for disrespecting the temple and preventing it from being a house of prayer (Matthew 21:13; Mark 11:17).