(Devarim 20:5) "Who is the man that has built a new house": This tells me only of one who has built. Whence do I derive (the same for) one who inherited, acquired, or received it as a gift? From "Who is the man?" (— in any event).
"a house": Whence do I derive (the same for) a straw loft, a cattle shed, a wood hut, and a treasure store? From "who has built" (— any manner of building). I might think then that also included are gateways, porticos, and porches; it is, therefore, written "house." Just as a house can be "inhabited," so, all that can be inhabited, to exclude the above, which cannot be "inhabited."
"and did not inhabit it": to exclude a (house) robber.
"let him go and return to his house": (Let him) heed the words of the Cohein at the battle formation and return,
"lest he die in the war": If he does not heed the words of the Cohein, in the end he will die in the war.
"and another man will inhabit it": I might think, his son or the son of his brother — It is written here "another," and elsewhere (Ibid. 28:30) "another." Just as "another" there is a gentile, so, "another" here.