Śaṅkaraon Brahma Sūtra 4.2.21

The rules as to dying by day and so on in order not to return are given by Srnr/ti for the Yogins only. And those two, viz. Yoga and SAhkhya are mere Srnr/ti, not of scriptural character. As thus it has a different sphere of application and is based on a special kind of authority, the Smrfti rule as to the time of dying has no influence on knowledge based on scripture. But, an objection is raised, we have such passages as the following one, ‘ Fire, light, the day, the light half of the month, the six months of the northern progress ; smoke, night, the dark half of the month, the six months of the southern progress’ (Bha. Gitd VIII, 24; 25); in which though belonging to Sm/'fti, we recognise the path of the gods and the path of the fathers just as determined by scripture! Our refutation, we reply, of the claims of Smr/ti applies only to the contradiction which may arise from the teaching of Smr/ti regarding the legitimate time of dying. ‘ I will tell you the time,’ &c. In so far as SmWti also mentions Agni and the other divinities which lead on the departed soul, there is no contradiction whatever.