Deuteronomy 25:9

Loose his shoe. Literally, his “sandal.” Jewish tradition indicates the shoe of the right foot. The deed here described was regarded as an act of indignity, inasmuch as failure to comply with the levirate law (see on verse 5) was looked upon as a mark of selfishness (see Ruth 4:6). The placing of the shod foot on property proclaimed either one’s contempt for it or one’s rightful ownership over it (Psalm 60:8; 108:9). Accordingly, the removal of the man’s shoe by his brother’s widow proclaimed the man’s unworthiness. He refused to do what was rightfully to be expected of him. Compare Song of Solomon 7:1 for the figure of the sandaled foot as a picture of beauty and desirableness. To go unshod was looked upon as degrading (2 Samuel 15:30; Isaiah 20:2, 4) or as a token of humility (Exodus 3:5; Joshua 5:15).

In his face. Jewish commentators usually interpret this as spitting on the ground “before his face.” This seems reasonable, because the preposition is not “upon,” but “by” or “before” (Deuteronomy 11:25; Joshua 10:8). Spitting before the face was thought to be humiliating (Numbers 12:14). This verb appears three times in the Hebrew Bible.

So shall it be done. The only exceptions were the high priest, who was not subject to the levirate law (Leviticus 21:13, 14), brothers living at a distance, and the aged.