in which he teaches that the Torah is like a mirror, in which each sees according to his own form
In it will you see…that a person will find that all the wisdom they can imagine or learn already indicated in the Torah, for the Torah is like a pure, natural and shining mirror; it will reflect the beholder's image, whatever shape is placed before it. Such is the Torah, each and every person makes sense of it in keeping with his or her understanding, and sees its image in it. Indeed, the Torah has six hundred thousand interpretations because each one of the six hundred thousand souls received an interpretation of the Torah, according to a literal, allegorical or esoteric meaning. Each soul will interpret Torah in keeping with the interpretation it received, and will find that particular interpretation in Torah, just like a mirror that reflects the shapes of all people, despite that they each have different shapes.
Ahava BaTa'anuguim, Tractate Avot, chapter 5, published by Orot HaHaim, Jerusalem (1987)