法華義疏 12.124

12.124

雖明會三歸一而不失開一為三。從經初以來明於正說，謂攝用歸體，故會三歸一；今辨流通從體起用，故於一說三。

Although it clarifies converging the three into the one, this does not forfeit opening the one into three. From the beginning of the sūtra onward it clarified the main teaching, meaning the integration of function into essence, and therefore converged the three into the one; now, in explaining the dissemination, it initiates function from essence, and therefore speaks of three within the one.