...which are the Seven Days of Creation... This is clear proof – for everything that was created is surely included in these seven days alone. Even according to the self-evident, simple meaning of the Bible, if everything came about in these seven days, it means that these seven days are sufficient to serve as the root. All the more so when we already know that kabbalistically, the seven days constitute the actual rule of the seven Sefirot, in that each one functions according to its power on that day. (See Ramban, Commentary on the Torah, Genesis 1:3.) Since everything came forth in the Seven Days of Creation, it must certainly be the case that everything came out of these Sefirot.