הלכה אויף משלי 3:22

It is a universal custom to write the word Shaddai (Almighty) on the other side of the Mezuzah, opposite the blank space between the two sections. As this word is written on the outside, the practice is unobjectionable. They, however, who write names of angels, holy names, a Biblical text or inscriptions usual on seals, within the Mezuzah, are among those who have no portion in the world to come. For these fools not only fail to fulfill the commandment but they treat an important precept that expresses the Unity of God, the love of Him, and His worship, as if it were an amulet to promote their own personal interests; for, according to their foolish minds, the Mezuzah is something that will secure for them advantage in the vanities of the world.^*A reproof to those who sell Mezuzoth to be worn as amulets !

He who delivers a prayer of charm upon a wound and reads also a verse of the Torah thereon, likewise one who reads a Verse so that a babe shall suffer no fear, or who puts a Sepher Torah or phylacteries upon a child so that he might fall asleep, such are not alone included among the enchanters and charmers but are even included among those who deny the Torah, for they are employing the words of the Torah as a cure for the body, whereas they are not so but only remedies for the soul¹⁴New sects, claiming remedial elements for physical ailments in Judaism, calling it “science”, evidently disagree with Maimonides and the Talmud. Yet, let Israel study this text. For physical ailment we have medical science. G. even as it is said: "And they will (shall) be life for thy soul" (Pro. 3.22). But a normally healthy person who reads Verses of the Torah or chapters of the Psalms, so that the righteousness of reading it shield him to escape suffering and accidents, lo, this is permitted.¹⁵Ibid. 90a: 101a; Shubu’ot, 16b; Tosefta, Sanhedrin, Chapter, 12; Shabbat, 121b. C. G.