פירוש על דברים 25:9

וירקה בפניו THEN SHE SHALL SPIT BEFORE HIS FACE — on the ground (not in his face) (Yevamot 106b).

ככה יעשה לאיש אשר לא יבנה את בית אחיו, he deserves this public embarrassment seeing he had refused to restore the house his deceased brother had begun to build when he betrothed his (now) widow. This reminds us of the statement in Shabbat 118 by Rabbi Yossi who did not refer to his wife as אשתי, “my wife,” but as ביתי, “my house.”

וענתה ואמרה ככה יעשה לאיש, "and she will say in reply: "so shall be done to any man, etc." The reason the Torah employs the term עניה, "reply," is because it is in answer to her brother-in-law who had refused to marry her.