(Devarim 20:6) "And who is the man that has planted a vineyard": This tells me only of one who has planted a vineyard. Whence do I derive (the same for) one who inherited, acquired, or received a vineyards as a gift? From "Who is the man" (— any manner of man).
This tells me only of a vineyard. Whence do I derive (the same for a plot containing) five food plants of five (different) kinds? From "that has planted," (fewer than five not being "planting"). I might think, even four food plants and five barren plants. It is, therefore, written "a vineyard," (these not being considered "a vineyard.")
R. Eliezer b. Yaakov says: I understand the verse as applying only to a vineyard, (and not as five food plants).
"and did not redeem" (in the fourth year): to exclude (from "returning") one who sunk vines. "and did not redeem it": to exclude one who engrafted them.
"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 redeem 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.