Ata' bin Abi Rabah عطاء بن أبي رباح · Chapters on the description of Paradise

"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.