Halakhah for Berakhot 41:7

And if you shall ask, why did they, may their memory be blessed, obligate to count the seven [cycles of] seven from that which is written, "And you shall count for yourself"; and [yet] we have never seen that the zav counts the days of his counting, nor the zavah the days of her counting, and even though it is written about them, "and he shall count for himself" (Leviticus 15:13), "and she shall count for herself" (Leviticus 15:28) - besides that they are obligated to pay attention to the days, but not that they be obligated to count them orally and recite a blessing on their count - the answer to this thing is what I prefaced at the beginning of my book: that every matter of the Torah is dependent upon the traditionally received explanation. And for the one that does not know this, how many verses will appear to be the opposite of one another, and how many difficulties and contradictions will arise? But for the one that knows it clearly, he will see that all of 'its ways are the ways of pleasantness and all of its paths are peace' and truth. And so, the tradition came to us that the command of, "And you shall count for yourself," of Jubilee requires an oral counting; whereas the command of counting, written about the zav and the zavah, is only paying heed to the days - and such is the practice of all of Israel in every place. "And even though they are not prophets, they are the children of prophets." And similar to this matter is that which we found in the Torah about the expression, remembering. As remembering is written about Amalek, and remembering [is written] about the [incident] of Miriam, and remembering is also written about the matter of leaving Egypt: And the tradition came to us about the remembering of Egypt to do it orally - and as they, may their memory be blessed, said (Berakhot 21a), about the blessing of "True and firm" (which mentions the leaving of Egypt), "It is from Torah writ." But with the other rememberings, it is enough for us with just remembering of the heart and paying heed to the things.