The disclosure was made by Modi himself on Monday.
After finishing his speech at the convocation ceremony, the prime minister took to the mike again and sought forgiveness from the varsity chancellor, vice-chancellor and other educationists for not accepting their offer.
"I am sorry but I have politely declined this offer as I do not consider myself worthy of it. I am a happy man as long as I can keep away from all this. Being present in the BHU premises itself is a great honour to me," he added.
Modi also said that he was forever indebted to the people of Varanasi for having reposed faith in him and electing him as their representative in parliament.
Varanasi is Modi's parliamentary constituency.
The BHU offered a D.Lit (Honoris Causa) to Modi but it was conveyed to the varsity authorities on Sunday by officials that the prime minister had declined it.