法華文句記 6.118

6.118

若善達二門，一門亦足，但一門若廢則二義俱虧，況表父慇懃先勸又誡，或時各逗機宜不同，化時不別共成一事。

If one thoroughly understands both approaches, one approach would indeed suffice; but if one approach were discarded, then both meanings would be deficient. Moreover, this expresses the father's earnestness in first exhorting and then warning; or at times they respectively suit different capacities, and when transforming, though not separate, they jointly accomplish a single purpose.