Rashi on Leviticus 25:29/רש"י על ויקרא כ״ה:כ״ט

1בית מושב עיר חומה A DWELLING PLACE IN A CITY WHICH HATH A WALL — i. e. a house situated in a city which has been surrounded by a wall since the days of Joshua the son of Nun (Sifra, Behar, Section 4 1).

2והיתה גאלתו THEN IT SHALL HAVE THE RIGHT TO BE REDEEMED [UNTIL THE COMPLETION OF THE YEAR OF ITS SALE] — Because it is stated about a field that one may redeem it after two years from the date of the sale and onwards at any time he pleases, but one may not redeem it during the first two years, Scripture was compelled to state specially with reference to this (the house) that just the opposite is the case — that if one wishes to redeem it in the first year he may do so, but after that he cannot redeem it.

3והיתה גאלתו THEN THE REDEMPTION OF IT — of the house — SHALL BE [TILL THE COMPLETION OF THE YEAR].

4ימים YEAR (lit., days) — the days of a full year are, briefly, termed “days”. Similar is: (Genesis 24:55) “Let the damsel remain with us a year (‎‎‏."(ימים