Is this Du'a authentic and who classified it?

Abu Sa’id Al-Khudri (radiyallahu ‘anhu) said: 'Whoever says "*Astaghfirullahal ‘Azim Alladi La Ilaha illa Huwal Hayyul Qayyumu wa atubu ilayh*" **five** times, his sins will be forgiven, even if they are like the foam of the ocean.' ( Al-Musannaf Ibn Abi Shaybah #30060 - [Mawquf narration] ) [I know that there are ahadith of reciting it **once** and **three** times, but I found this one too which is also intersting, therefore I would like to know who commentated/authenticated it with a source]