Horayos2: 4
אֵין חַיָּבִין עַל עֲשֵׂה וְעַל לֹא תַעֲשֶׂה שֶׁבַּמִּקְדָּשׁ, וְאֵין מְבִיאִין אָשָׁם תָּלוּי עַל עֲשֵׂה וְעַל לֹא תַעֲשֶׂה שֶׁבַּמִּקְדָּשׁ.  אֲבָל חַיָּבִין עַל עֲשֵׂה וְעַל לֹא תַעֲשֶׂה שֶׁבַּנִּדָּה, וּמְבִיאִין אָשָׁם תָּלוּי עַל עֲשֵׂה וְעַל לֹא תַעֲשֶׂה שֶׁבַּנִּדָּה. אֵיזוֹ הִיא מִצְוַת עֲשֵׂה שֶׁבַּנִּדָּה? פְּרֹשׁ מִן הַנִּדָּה. וּמִצְוַת לֹא תַעֲשֶׂה? לֹא תָבֹא אֶל הַנִּדָּה.
They are not liable for the positive commandment or the negative commandment concerning the Temple; and they do not bring an asham talui for the positive commandment or the negative commandment concerning the Temple.  But they are liable with respect to the positive commandment and the negative commandment concerning the menstruant; and they bring an asham talui for the positive commandment and the negative commandment concerning the menstruant. What is the positive commandment concerning the menstruant? Separate from the menstruant. And the negative command? Do not cohabit with a menstruant.