《史记·八书·律书》
所以说音律开始于宫声，终结于角声；数开始于一，终结于十，万物生成于三；万物的生气开始于冬至，以年为周期循环往复。
故曰音始于宫，穷于角；数始于一，终于十，成于三；气始于冬至，周而复生。
Therefore, it is said that the musical scale starts from the palace tone and ends with the corner tone; the number starts from one and ends with ten, and all things are generated from three; the vitality of all things begins from the winter solstice and circulates repeatedly with the year as the cycle.