When the four previous sons of Brahma, the sages Sanaka, Sanatana, Sanandana and Sanat-kumara, refused to obey their father, Brahma was mortified, and his anger was manifested in the shape of Rudra. That incident was not forgotten by Brahma, and therefore the obedience of Manu Svayambhuva was very encouraging. From the material point of view, the four sages disobedience to the order of their father was certainly abominable, but because such disobedience was for a higher purpose, they were free from the reaction of disobedience. Those who disobey their fathers on material grounds, however, are surely subjected to disciplinary reaction for such disobedience. Manus obedience to his father on material grounds was certainly free from envy, and in the material world it is imperative for ordinary men to follow the example of Manu.