Parashas Vayeilech · Passuk 31:18
Yet I will keep My countenance hidden on that day, because of all the evil they have done in turning to other gods.
Torah Temimah points to Chullin 139b (חולין קל"ט ב').
English: One might have thought that with regard to this valuation too, the halakha should be so, i.e., if money from a valuation is stolen or lost, the owner does not bear financial responsibility for it. Therefore, the verse states: “And he shall give your valuation on that day,” indicating that the valuation money is non-sacred until it enters the possession of the Temple treasurer, and that the owner bears responsibility for it until that time. Evidently, even with regard to valuations, the consecrator bears financial responsibility, in contradiction to the statement of Rav Hamnuna. Rather, if a statement was stated, this is what was stated: Rav Hamnuna says that everyone concedes with regard to valuations that even if one did not say: It is incumbent upon me, one bears financial responsibility for it, as it is written: “And he shall give your valuation,” indicating that the valuation money is non-sacred until it enters the possession of the Temple treasurer. § The mishna states: There are more stringent elements in the covering of the blood than in the sending away of the mother from the nest, as the covering of the blood applies to undomesticated animals and birds, to animals and birds that are readily available in one’s home, and to animals and birds that are not readily available; and the sending of the mother from the nest applies only to birds that are not readily available. With regard to the mitzva of sending away the mother, the Sages taught in a baraita: The verse states: “If a bird’s nest happens before you on the way, in any tree or on the ground, with fledglings or eggs, and the mother is resting upon the fledglings, or upon the eggs, you shall not take the mother with the young; you shall send the mother, but the young you may take for yourself” (Deuteronomy 22:6–7). What is the meaning when the verse states all the various details contained in it? Since it is stated: “You shall send [shalle’aḥ teshallaḥ] the mother, but the young you may take for yourself,” one might have thought that the doubled verb “shalle’aḥ teshallaḥ” indicates that one must search even in the mountains and hills in order to find a nest with which to perform this mitzva. Therefore, the verse states: “If a bird’s nest happens,” indicating that one is obligated to send away the mother only when it confronts you; one is not required to seek out a nest. The baraita continues: The word “nest” indicates that this mitzva applies in any case, even to a nest with only a single chick or egg. The word “bird’s” indicates that the mitzva applies only to kosher birds, and not to non-kosher birds. The term “before you” indicates that the mitzva applies to a nest that is on private property, e.g.
Derash on the verse (Bavli sugya) — not a formal named middah of the 13
The Gemara uses this passuk inside a sugya (question, proof, or illustration). That is classical derash, but not labeled here as one of R' Yishmael’s 13 unless the move is explicit.
The doubled hiding of the face intensifies the prior warning: continued turning to other gods meets a deeper concealment, not a shallow punishment.