'And he said, Behold now, my lords, turn in. I pray you, into your servant's house, and tarry all night, and wash your feet, and ye shall rise up early, and go on your ways. And they said, Nay; but we will abide in the street all night.'
In Isaiah (7:20) reference was made to the hair of the feet. Most authorities interpret this passage to mean pubic hair. By sexualizing the feet, there was need to cover them from uninvited gaze. In the vision of the Lord's glory, Isaiah described the six wings of the seraphims.
'and with twain he covered his feet.'
Centuries later, Christian art avoided showing feet of the Devine with only the more risque artists risking ex communication, by tempting viewers to glimpses of uncovered feet. Angels were painted with large wings, which covered their feet, hence, a representation of modesty. The term shoe, which had its derivation in Old English (Anglo Saxon), describes a cover but not as protection, instead it meant to partially conceal, in an alluring manner. In Biblical times feet were not sexually attractive but could become so, when embellished with sandals. The penis metaphor is most obvious in the Book of Ruth.
'And it shall be, when he lieth down, that thou shalt mark the place where he shall lie, and thou shalt go in, and uncover his feet, and lay thee down ; and he will tell thee what thou shalt do.'