Halakhah sobre Êxodo 22:28

To not skip in the laws of produce: To not skip in the laws of produce - some of them over [others] of them - but we should rather extract them in order. The elucidation of the matter is that after the wheat is threshed and cleaned, it is tevel, and the understanding of tevel is produce that has not been separated. And the obligation upon us with it, is to first remove the priestly tithe from it. And by Torah writ, even one [kernel of] wheat exempts the threshing floor (Kiddushin 29b), but the Sages said that [the mandatory amount] is one part in fifty. And afterwards, the obligation upon us from that which is left over is to remove the tithe from it, and that is called the first tithe. And afterwards, the obligation upon us from that which is left over is to remove another tithe, and that is the second tithe. And the priestly tithe is given to the priest, the first tithe to the Levite, and the second tithe [is kept,] that it be eaten by its owner in Jerusalem. And we are obligated to separate these portions from the produce in this order. And upon this came the preventing, that we not do first from this what is fitting to delay, and not delay what is fitting to do first (Mishnah Terumot 3:10) - as it is stated (Exodus 22:28), "Your fullness and your offering you shall not delay." And it is as if it stated, "From your fullness and your offering, you shall not delay what is fitting to do first."

And that is that He commanded us to redeem the firstborn man, that we should give the money to the priest. And that is His saying, "you shall give me your firstborn sons" (Exodus 22:28). And He explained to us how this giving should be: And it is that we redeem him from the priest; and it is as if [the priest] already acquired him, and we purchase him from him for five sela - and that is His saying, "but surely redeem the firstborn man" (Numbers 18:15). And this commandment is the commandment of redeeming the son. And women are not obligated in it - indeed it is one of the commandments of the son that is upon the father, as it is explained in Kiddushin (Kiddushin 29a). And all of the laws of this commandment have already been explained in Bekhorot. However Levites are not obligated in it. (See Parashat Mishpatim; Mishneh Torah, Firstlings.)