This is the reason for the institution of the seven lower and three upper Sefirot. The seven lower Sefirot are the root of the created realms and beings in their essential existence, which is unchanging. And it is the seven lower Sefirot that produce the different aspects of the creation. From Chessed there is a constant flow of water and from Gevurah fire, while Yesod is always the source of the structure.
From Chessed comes wisdom, from Gevurah wealth, from Tiferet life, and so on. However, any increase or decrease in degree or status in all these aspects depends upon the three first Sefirot. When they shine strongly in the seven lower Sefirot, the latter will bring forth superior offspring in a state of greater repair. But if they shine in only a limited way, the offspring of the seven lower Sefirot will be lowly and lacking in repair.
Thus the seven lower Sefirot are the root of the created realms and beings while the three first Sefirot are crowns over them.