Someone asked Sayyiduna Ali (may Allah be pleased with him) about Witr, whether it is obligatory. He replied that Witr does not have definitive proof from the Noble Qur'an like the obligatory prayers, but its obligation is established from the Sunnah of the Prophet (peace and blessings be upon him) and his companions (may Allah be pleased with them), and they always performed it.

Abdu Khair (may Allah have mercy on him) says that once Sayyiduna Ali (may Allah be pleased with him) asked for water to perform ablution and said: Where are those people who think that in no situation is it permissible to drink water while standing? Then he took the vessel and drank its water while standing, then performed a light ablution, wiped over his shoes, and said: This is the ablution of a pure person who is not without ablution; this is the way the Prophet (peace and blessings be upon him) used to perform ablution.

On one occasion, Sayyiduna Ali (may Allah be pleased with him) washed each part of the body three times while performing ablution and drank the leftover water from the ablution, then said: I saw the Prophet (peace and blessings be upon him) doing the same.

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When any one of you sneezes, he should say «اَلْحَمْدُ لِلّٰهِ» , those around him should say «يَرْحَمُكَ اللّٰهُ» , and the one who sneezed should reply to them with «يَهْدِيْكُمُ اللّٰهُ وَيُصْلِحُ بَالَكُمْ» ."

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When any one of you sneezes, he should say «اَلْحَمْدُ لِلّٰهِ عَلَي كُلِّ حَالٍ» , those around him should say «يَرْحَمُكَ اللّٰهُ» , and the one who sneezed should reply to them: «يَهْدِيْكُمُ اللّٰهُ وَيُصْلِحُ بَالَكُمْ» ."

Abdu Khair (may Allah have mercy on him) says that once we were sitting in the mosque when Sayyiduna Ali (may Allah be pleased with him) came and said, "Where is the one who asked about Witr?" Whoever among us had prayed one rak'ah quickly joined for the second rak'ah, and we all gathered around Sayyiduna Ali (may Allah be pleased with him). He said: "The Prophet (peace and blessings be upon him) initially used to pray Witr in the first part of the night, then he started praying it in the middle part, and then he continued to pray it at the time when dawn was about to break."

Abdullah bin Nafi’ (may Allah have mercy on him) says that once Sayyiduna Abu Musa (may Allah be pleased with him) came to visit Sayyiduna Imam Hasan (may Allah be pleased with him) to inquire about his health. Sayyiduna Ali (may Allah be pleased with him) said to him:“Have you come with the intention of visiting the sick or just to meet him?”He replied,“I have come with the intention of visiting the sick.”Sayyiduna Ali (may Allah be pleased with him) said:“I heard the Prophet (peace and blessings be upon him) say: ‘When a person visits his Muslim brother in the morning to inquire about his health, seventy thousand angels accompany him, and each of them prays for his forgiveness until the evening, and a garden is fixed for him in Paradise. And if he visits in the evening, then seventy thousand angels accompany him, and each of them prays for his forgiveness until the morning, and a garden is fixed for him in Paradise.’”

Abdullah bin Nafi’ (may Allah have mercy on him) says that once Sayyiduna Abu Musa (may Allah be pleased with him) came to visit Sayyiduna Imam Hasan (may Allah be pleased with him) to inquire about his health. Sayyiduna Ali (may Allah be pleased with him) said to him:“Have you come with the intention of visiting the sick or just to meet?”He replied,“I have come with the intention of visiting the sick.”Sayyiduna Ali (may Allah be pleased with him) said:“I heard the Prophet (peace and blessings be upon him) say: ‘When a person visits his Muslim brother in the morning, seventy thousand angels accompany him, and each of them prays for his forgiveness until evening, and a garden is fixed for him in Paradise. And if he visits in the evening, then seventy thousand angels accompany him, and each of them prays for his forgiveness until morning, and a garden is fixed for him in Paradise.’”

Sayyiduna Ali (may Allah be pleased with him) said: I used to suffer from excessive discharge of madhy (pre-seminal fluid). I asked the Prophet (peace and blessings be upon him) about its ruling, so he said:“Ghusl is obligatory due to semen, and wudu is obligatory due to madhy.”

Aamir says that there was a woman named Shurahah whose husband was not present with her; he had gone to Syria. This woman became pregnant. Her master brought her to the service of Sayyiduna Ali (may Allah be pleased with him) and said that this woman had committed adultery. The woman also confessed. Sayyiduna Ali (may Allah be pleased with him) first gave her fifty lashes, then on Friday he carried out the punishment of stoning to death (rajm) upon her, and had a pit dug for her up to her navel. I was also present at that time. Then Sayyiduna Ali (may Allah be pleased with him) said that stoning is the Sunnah of the Prophet (peace and blessings be upon him). If this crime had been proven by the testimony of a witness, then the one who testified would have started the stoning, because the witness first gives testimony and then throws the stone. But since this crime was proven by her confession, now I will be the first to throw a stone at her. Thus, Sayyiduna Ali (may Allah be pleased with him) began, and afterwards people started throwing stones at her; I was also among them, and by Allah! I was also among those who sent this woman to Allah.