Emor, Chapter 17
1)1(Vayikra 23:41) ("And you shall celebrate it at a festival to the L–rd, seven days a year, a statute forever throughout your generations; on the seventh month you shall celebrate it.") "And you shall celebrate it as a festival to the L–rd seven days": Because it is written "And you shall celebrate it as a festival to the L–rd seven days," I might think that one must bring a festive offering (chagigah) all seven days; it is, therefore, written you shall celebrate it" — one day alone.