Brahma Sutras – According to Shankara 3-3-2
Topic 2 - Particulars of identical Vidyās mentioned in different places or Śākhās are to be combined into one meditation
उपसंहारोऽर्थाभेदाद्विधिशेषवत्समाने च ॥ ५ ॥
upasaṃhāro’rthābhedādvidhiśeṣavatsamāne ca || 5 ||
upasaṃhāraḥ—Combination; arthābhedāt—since there is no difference in the object of meditation; vidhiśeṣavat—like the subsidiary rites of a main sacrifice; samāne ca—and in the Upāsanās of the same class.
5. And in the Upāsanās of the same class (mentioned in different Śākhās) a combination (of all the particulars mentioned in all Śākhās is to be made), since there is no difference in the object of meditation, just as (a combination of) all subsidiary rites of a main sacrifice (mentioned in different Śākhās is made).
From what has been discussed in the previous Sutras it is clear that the Vidyās described in different Śākhās will have to be combined in the Upāsanā, since their object after all is one.
The particulars mentioned in other Śākhās than one’s own are also efficacious, and as such one has to combine all these, even as one does with respect to subsidiary rites like Agnihotra, connected with a main sacrifice, mentioned in several Śākhās.