Question

Hello, honored Rabbi. The Rabbi says that according to Maimonides, we learn from the word "linen"—which Scripture repeated in order to make it indispensable to the law—that the garments must be made of six threads, but only regarding garments about which it explicitly says they are to be made of linen. This is because, in his view, interpretation expands the law rather than uncovers it; therefore, since the rule that "Scripture repeated it to make it indispensable" applies only to linen garments according to the Torah, it does not apply to garments described merely as "fabric."
According to Maimonides, we expound the final occurrence of the word "linen" to teach that the requirement to make them from six threads is indispensable, because Scripture repeated it to make it indispensable. So from what I understand, according to Maimonides the rule "Scripture repeated it to make it indispensable" makes even rabbinic laws indispensable as well. Therefore, even though the Torah does not say "linen" regarding "fabric" (according to Maimonides), there is still a rabbinic law derived from the word "linen" that those too must be made of six threads. If so, why does the final "linen" not make this law too indispensable for them? In other words, we should learn from the final word "linen" that the rule—"even where it says only 'fabric' and not 'linen,' make them of six threads"—is indispensable.
Thank you very much for all the effort and the enlightening lessons!