Among the impressive divine miracles and virtues of the Commander of the Faithful Ali Ibn Abi Taleb (peace be upon both of them) is the sun returning to him (peace be upon him) twice, once during the life of the Holy Prophet (Allah's prayers be upon him and upon his holy Household) and once after his death (Allah's prayers be upon him and upon his holy Household).
After the death of the Holy Prophet (Allah's prayers be upon him and upon his holy Household), when Imam Ali (peace be upon him) wanted to cross the Euphrates in Babylon coming from the war with the Kharijites, many of his companions were busy making their animals and belongings cross the river, while he prayed 'Asr leading a group, but the others did not finish crossing the river until sun set and so they missed the prayer time and missed praying behind him. When he heard them talking about it, he prayed the Almighty Allah to return the sun for him so he can gather all his companions for the prayer of 'Asr so they can pray on time. His prayer was answered, and the sun returned to the state when the sun is on 'Asr time, and once they finished the prayer, the sun went down, and they started cheering, praising the Almighty and asking for His forgiveness, and thanking Him for the miracle they could witness. The news have then spread in the horizons and among people.
It is narrated from Imam Mohammad Al-Baqer (peace be upon him) that he said to Abu Baseer: (part from a long narration) "The sun returned to him once in Medina, and twice in Iraq." And maybe he (peace be upon him) meant the times people have witnessed it, in addition to the times that the infallible Imam (peace be upon him) knows.
It is also narrated from Imam Al-Baqer (peace be upon him) saying: "When Imam Ali (peace be upon him) was going to Nahrawan, he reached the land of Babylon and it was time for afternoon prayer, but he kept going and did not stop. Before leaving the land, the sun set. Everyone got off his horse and said his prayer except for Malik Ashtar. He said “I do not say prayer if Ali (peace be upon him) does not do so”. After leaving land of Babylon, Ali (peace be upon him) got off and said to Malik “You, Malik! This land was salt marsh and prayer in there is not acceptable. Whoever said prayer in there should do it again”. Imam Al-Baqer (peace be upon him) says “Imam turned to Qibla and said three sentences neither in Arabic nor Persian. By the end, the brilliant sun returned to sky again. He said his prayer and by the end of his prayer, a noise like cutting wood by a saw could be heard”.