Midrash su Deuteronomio 12:5

2) I might think (that he could bring them) on any festival that he desired. It is, therefore, written (Devarim 12:5-6) "And you shall come there (to the Temple) and you shall bring there" (the same). If to permit, it had already been permitted. If to make mandatory, it has already been made mandatory. If so, why is it written? (To make it mandatory for him to bring them) on the first festival (of the three festivals) that arrives (after they were due).

7) "And thirty days (and three days shall she abide in the blood of cleanliness"): I might think, either consecutive or scattered; it is, therefore, written "thirty day" (lit.) — Just as one day is consecutive, so are thirty. I might then think that the thirty are consecutive, but the three may be either consecutive or scattered; it is, therefore, written "and thirty days and three days" — Just as the thirty are consecutive, so the three are consecutive. Why need "thirty-three days" be written? (i.e., Since we find that the cleanliness days for a female are doubled, those for a female being sixty-six (viz. Devarim 12:5), we understand that those for a male must be thirty-three.) I might reason: If for a female, for which the days of uncleanliness are many (fourteen), the days of cleanliness are many (sixty-six), than for a male, for which the days of uncleanliness are few (seven), how much more so should the days of cleanliness be many! It is, therefore, written "thirty-three days." "she shall abide": to include a woman who experienced labor pains (and bleeding) in the midst of the eleven days (separating her niddah times) as being clean of zivah uncleanliness, (the assumption being that the bleeding was caused by the contractions and not by the zivah). I might think that she would likewise be clean if she experienced this in the midst of her niddah time; it is, therefore, written (Vayikra 12:2) "(any blood that she sees) in (the time of) her niddah flow, she shall be unclean." ("And thirty-three days she shall abide in) the blood of cleanliness": Even if she sees blood (in that period) she is clean.

Rabbi Yehudah ben Shimon began, "'After the Lord your God shall you walk' (Deuteronomy 12:5). But is it possible for a man of flesh and blood to walk after the Holy One, blessed be He, the One about Whom it is written (Psalms 77:20), 'Your way is in the sea and Your path is in many waters?' And you say, 'After the Lord shall you walk?' 'And to Him shall you cling.' But is it possible for flesh and blood to go up to the Heavens and to cling to the Divine Presence, about Whom it is written (Deuteronomy 4:24), 'As the Lord, your God, is a consuming Fire,' and it is written (Daniel 7:9), 'His throne is sparks of fire,' and it is written (Daniel 7:10), 'A river of fire pulses and goes out before Him.' And you say, 'And to Him shall you cling?' But rather, the Holy One, blessed be He, from the very beginning of the creation of the world, only occupied Himself with plantation first. Hence it is written (Genesis 2:8), 'And the Lord God planted a garden in Eden.' You also, when you enter into the land, only occupy yourselves with plantation first. Hence it is written, 'When you shall come to the land.'"