《史记·八书·律书》
蕤宾的意思，是说阴气幼小，所以称为蕤；衰落的阳气已不主事，所以称为宾。
蕤宾者，言阴气幼少，故曰蕤；痿阳不用事，故曰宾。
Ruyi means that Yin qi (energy) is young and tender, therefore it is called Ruyi; the declining Yang qi is no longer in charge, therefore it is called Bin.