Midrash su Deuteronomio 11:20

(Ib. b) We are taught that R. Nathan says: "As a punishment for not fulfilling vows, the wife of the man dies, as it is said (Pr. 22, 27.) If thou have nothing to pay, why should He take away thy bed from under thee?" Rabbi says: "For the sins of [unfulfilled] vows children die when still young, as it is said (Ecc. 5, 5.) Suffer not thy mouth to cause thy body to sin, etc. Why should God be angry because of thy voice, and destroy the work of thy hand? We must say that this refers to the sons and the daughters of man." There is a difference of opinion between R. Chiya b. Abba and R. Jose; one said: "The sin of not having Mezuzoth is the cause of children's death," and the other said: "The sin of being remiss in the study of the Torah is the cause of children's death." The one who laid the affliction to the sin of Mezuzoth, holds that a passage can be connected with another one preceding it and thus explained, but not with a passage that comes before the preceding one; and the one that laid the affliction to the sin of being remiss in the study of the Torah, holds that passage can be connected even with one that comes before a preceding passage, and thus explained. There is also a difference of opinion between R. Meier and R. Juda. One said: "It (the death of children) is due to the sin of Mezuzoth," while the other said: "It is due to the sin of Tzitzith." It is right according to him who said it is due to the sin of Mezuzoth, for it is written (Deu. 11, 20.) And thou shalt write them upon the doorposts of thy house, and immediately following is written In order that your days and the days of your children may be multiplied; but according to the one who said it is due to the sin of Tzitzith, what is his reason? R. Cahana, and according to others, Shila Mari, said: "Because it is written (Jer. 2, 34.) Also on the end of thy skirts is found the blood of the souls of the innocent needy ones." R. Nachman b. Isaac said: "The one who says it was due to the sin of Mezuzoth, derives his opinion from this (Ib.) Not while breaking in (thy house) didst thou find them, i.e., making the doors like a breaking in (without a Mezuzah)."

Behold, thou art fair; that is, in the performing the deeds of your fathers. Behold, thou art fair implies in your home, and behold, thou art fair in the field. In your home alludes to the house that has a mezuzah upon it; And thou shalt write them upon the doorposts of thy house (Deut. 11:20). In the field refers to the field that contains the heave-offerings, tithes, gleanings, the poor man’s sheaves, and the corners left for the needy. Behold, thou art fair in thy house refers to the roof of your house, as is said: When thou buildest a new house, then thou shalt make a parapet for thy roof (Deut. 22:8) Behold, thou art fair in this world; behold, thou art fair in the world-to-come.