There is an interesting story of how Sri Adi Shankaracharya came to write about the commentary on Vishnusahastranama. First he wanted to write on Lalita Sahastranama..so he sent his disciple Padmapada to fetch the scroll which contained Lalita Sahastranama, when the disciple came back and gave the scroll to Adi Sankara , he realised it was Vishnusahastranama. This happened couple of times , finally Adi Sankara asked Padmapada what the matter was and he said what to do...when I go inside there is one girl standing inside the room and handing me the scroll and asking me to give it to you. So immediately Adi Sankara went inside. It was goddess Ambal herself....saying rather than write about me why don't you write about my brother's names..

According to another legend, it is said that he heard a voice asking him to write about Vishnusahastranama. As it may be, this was the first commentary he wrote. Adi Sankara is known as "Bhashyakara" that is writer of commentary. On various topics he has written commentaries, but he started writing with Vishnusahatranama....