“After some days of the death of the Holy Prophet (sawa), Imam ‘Ali met one of the two men (Abu Bakr) and advisd him to remember Allah and the Day of Allah (Day of Resurrection) and told him, ‘Do you wish to meet the Prophet now so that he may advice you to forbid (evil) and enjoin (good)?’ He replied in the affirmative and ‘Ali took him to Masjid al-Quba and showed him the Prophet of Allah who was seated therein.
The Prophet of Allah said to him, ‘O so and so! Do you pledge with me in this manner that you will give the caliphate (back) to ‘Ali as he (‘Ali) is the Commander of the Faithful?’ Seeing this, he returned back with ‘Ali and resolved to hand the caliphate over to him but his friend (‘Umar) did not permit it (to occur).”
He said, “This is nothing but apparent magic and the renowned sorcery of the Bani Hashim! You forget that one day, we were with Ibn Abi Kabshah (meaning the Noble Prophet). He signaled towards the two trees and they joined together, then he went behind and answered the call of nature. Then he gesntured towards them and they separated from one another.”
The first one (Abu Bakr) said, “Now that you have reminded me about this matter, I too recall an incident. The Prophet and I had taken shelter in the cave (of Thawr). He stretched his hand towards my face and motioned with his feet at which time I saw a river. He then showed me Ja’far (al-Tayyar) and his companions who were seated on a boat and sailing.”
However even after all of this, he (Abu Bakr) was influenced by his friend (‘Umar) and changed his mind to hand over the caliphate to ‘Ali.
House of Sorrows Translation of Baytul AhzanShaikh Abbas Al – Qummi