The Prophet´s visit to Paradise and his informing his Ummah about what he saw there

 This is one of the clearest proofs on the existence of Paradise. The Prophet, blessings and peace of Allah be upon him, had visited Paradise and entered it in a state of wakefulness when he was taken on the night journey to the heavens. He informed his followers about what he saw there. Allah says in this regard:

´´Glorified (and Exakted) is He (Allah) (about al that (evil) they associate with Him) Who took His slave (Muhammad salla alayhi wa sallam) for a journey by night from Al-Masjid-al-Haraam (at Makkah) to the farthest mosque (in Jerusalem), the neightborhood whereof We have blessed, in order that We might show him (Muhammad) of Our Ayaat (proofs, evidences, lessons, signs, etc.). Verily, He is the All-Hearer, the All-Seer.´´ (Al-Israa´ 17:1)

´´And indeed he [Muhammad (blessings and peace of Allah be upon him] saw him [Jibreel (Gabriel)] at a second desvent (i.e. another time) near Sidrat-ul-Muntaha (a lote-tree of the utmost boundary over the seventh heaven beyond which none can pass). Near it is the Paradise of Abode. When that covered the lote-tree which did cover it! The sight [of Prophet Muhammad (blessings and peace of Allah be upon him)] did see of the Greatest Signs, of his Lord (Allah).´´ (An-Najm 53:13-18)

Al-Bukhari and Muslim reported onthe authority of Anas bin Malik, may Allah be pleased with him, who narrated the story of Israa´ and Mi´raj from the Prophet, blessings and peace of Allah be upon him,. Part of the narrations goes thus:

´´The Gabriel took me till we reached Sidratul-Muntaha (Lote Tree of the utmost boundary) which was shrouded in colors, indescribable. Then I was admitted into Paradise where I found small (tents or) walls (made) of pearls and its earth was of Musk.´´