# I will answer you

Here "you" refers to Yahweh's servant.

# in a day of salvation

 "when the time comes for me to save you" 

# give you as a covenant for the people

"make you be the mediator of a covenant with the people" 

# to rebuild the land

"to rebuild the ruined places in the land" 

# to reassign the desolate inheritance

"to reassign the desolate land to the people of Israel as their inheritance"