Jami` at-Tirmidhi 2531
جامع الترمذي#2531SahihUbadah bin As-Samit narrated that the Messenger of Allah (s.a.w) said:"In Paradise, there are a hundred levels, what is between every two levels is like what is between the heavens and the earth. Al-Firdaus is ts highest level, and from it the four rivers of Paradise are made to flow forth. So when you ask Allah, ask Him for Al-Firdaus." Another chain reports a similar narration
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 38:9