According to both Smartha and Madhwa traditions, Vyasa is said to have met Adi Shankaracharya and Madhvacharya respectively, and even endorsed their commentaries on the Brahma Sutras.
This is what an excerpt of the Shankara Digvijaya, the most accepted biography of Adi-Shankaracharya, says about the meeting:
Once, seated on the banks of the Ganga, the Acharya was teaching his commentaries to his disciples till late in the noon. Finding the disciples exhausted, the Acharya closed the session and got up, when he was confronted by an old Brahmana with the question: "What are you teaching, Sir? And may I know who you are?" Thereupon the disciples. intervened and said: "This is our teacher, the great Acharya Sankara, the master of all the Upanishads, who has established the doctrine of Non-dualism through his commentaries on Sariraka-sutras (Brahma-sutras)." The Brahmana thereupon remarked: "O Sannyasin teacher, this seems unbelievable. These people say that you have commented on the Sutras of Vyasa. If you are as learned as that, let me hear you expound anyone Sutra of Vyasa."..... The Brahmana thereupon quoted the first Sutra) from the third chapter of Brahma-sutras, and asked Sankara to explain it...... Thereupon Sankara answered the criticisms and attacked the thesis of the Brahmana in several ways. .....On hearing the surprising revelation of the identity of the opposing scholar, Sankara at once saluted him with palms closed, sang his praise with a new hymn he composed on the spot, and said: "Thy deer-skin covering, rain-cloud complexion, white sacred thread, matted locks, and shining diadem reveal thee to be Vyasa himself. Thy life and work have mitigated the banefulness of this age of Kali. If thou approvest of the commentary I have produced on thy Aphorisms which deal exhaustively with Truth transcendental and temporal, then deign to pardon my lapses and reveal thy true nature to me." At these words, the sage revealed his real form with matted locks like a heap of golden wires...
:.....the illumined sage sat on a seat offered to him and began to speak as follows to Sankara who kept standing before him in all humility: "....... Do not think that I came to you for a mere debate. In the assembly at the heavenly abode of Siva I heard from the Siddhas that you have written a commentary on Vedanta Sutras. I was very glad to hear this, and I came desirous of seeing you, the commentator." Hearing these words. the great Sannyasin, Sankara, ..... spoke to the sage, his body covered with horripilations indicative of his inward joy: ...... To the luminous sun of thy Sutras shedding light on all doctrines of the Vedanta, please pardon me for this foolhardy venture of mine, and condescend to give a critical estimate of it, correcting whatever mistake thou findest in it."
From the hands of Sankara who was addressing him thus, Vyasa took a copy of the Bhashya and went through its contents, noting its clarity and profundity. He appreciated very much its methodology, consisting first in elucidating the meaning of the Sutras in simple words synonymous with them, then refuting the opposite views in an original way with the help of sound reasoning, and next, giving a positive exposition of the doctrine in words that are in agreement with reason and scriptures. He then said: "Dear boy, I have gone through your commentary carefully. In no way can it be called a foolhardy enterprise as you characterised it. You asked me to make a critical estimate of it, showing its merits and demerits. To do that will, indeed, be foolhardy. You are unrivalled in your grasp of the technique of inter- preting Vedic passages. You have unusual mastery of grammar... How then can there be any mistakes in your writings?..... Who else but a man of your caliber can give such a clear and lucid commentary on my aphorisms, terse in language, vast in meaning, and subtle in implications? Scholars say that it is difficult to understand what exactly these aphorisms mean; so terse are they in expression. Hence it is said that the difficulty of anyone who interprets them is in no way less than that of the one who composed them. Who else but an incarnation of Siva could grasp all the implications of these Sutras and produce a commentary on them, thereby elevating the Vedas to their dignified position from the degradation to which they have been subjected by the Samkhyas and other philosophers, Though you share the same name 'Sankara' with God Siva, you are unique and seem to excel even that Divinity· in many respects.... Many have made commentaries on my aphorisms in the past and many will do so in future also. But none of them has been able to know their real meaning as I conceive it; only you have. With the help Of this commentary on the Vedanta Sutras and many allied writings, may you refute all opposing doctrines and, thereby, become famous in the world!...... May your commentary shine till the end of time! During the rest of your life, may you uproot the doctrines of those who oppose the Advaita philosophy, and establish in them faith in this doctrine of the unity of all existence!"
You can read about the meeting between Madhvacharya and Vyasa in details in Chapter 8 of Sumadhvavijaya.
Now, coming, to my question, are there any other Vedantic acharyas such as Ramanujacharya or Nimbarkacharya who are believed to have met Vyasa, and even their corresponding commentaries on the Brahma Sutras endorsed by Vyasa Himself, according to their respective traditions?
