Sayyiduna Ibn Mas'ud (may Allah be pleased with him) narrates that whoever buys an animal with tied udders should return it and give along with it one sa’ of wheat (so that it equals the amount of milk used), and the Prophet (peace and blessings be upon him) forbade going out of the city to meet traders before they arrive. And the Prophet (peace and blessings be upon him) forbade going out of the city to meet traders before they arrive.

It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There is no arbitrator—who decides between people—except that he will be stopped on the Day of Resurrection, an angel will be holding him by the back of his neck and will make him stand over Hell. Then he will raise his head and look towards Allah Almighty. If it is commanded from there that he is a sinner, then the angel will throw him into Hell, where he will tumble for forty years."

It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "The cycle of day and night and time will not end, that is, the Hour will not be established until a man from my Ahl al-Bayt rules over the Arabs whose name will correspond to my name."

Abdullah bin Utbah says that once someone came to Sayyiduna Ibn Mas’ud (may Allah be pleased with him) and asked this question: If a man marries a woman without specifying a dowry, and before consummation he dies, what is the ruling? Sayyiduna Ibn Mas’ud (may Allah be pleased with him) did not give an immediate answer, and the questioners left. After some time, they came again and asked him the same question. He said: I will state before you the conclusion I have reached through my own reasoning; if my answer is correct, it will be by Allah’s guidance, and if it is wrong, it will be from myself. The decision is that this woman should be given the dowry similar to that of women like her, she will also inherit, and she must observe the waiting period (‘iddah). Upon hearing this decision of Sayyiduna Ibn Mas’ud (may Allah be pleased with him), a man from the tribe of Ashja’ stood up and said: I bear witness that the Prophet (peace and blessings be upon him) gave the same ruling in this matter. Sayyiduna Ibn Mas’ud (may Allah be pleased with him) said: If there is any witness to this, present him. So Sayyiduna Abu al-Jarrah (may Allah be pleased with him) testified to it.

The previous hadith is also narrated through this second chain, however, there is an addition in it that the Prophet (peace and blessings be upon him) gave the same verdict in the case of Barwa' bint Washiq, and this was testified by Sayyiduna Abu Sinan and Sayyiduna Jarrah (may Allah be pleased with them both), who were men from the tribe of Ashja'.

Sayyiduna Ibn Mas’ud (may Allah be pleased with him) narrates that when we used to sit in Tashahhud with the Prophet (peace and blessings be upon him), we would say:“Peace be upon Allah from His servants, peace be upon Jibreel, peace be upon Mika’eel, peace be upon so-and-so and so-and-so.”When the Prophet (peace and blessings be upon him) heard us saying this, he said:“Allah Himself is the embodiment of peace, so when any one of you sits in Tashahhud, he should say: «التَّحِيَّاتُ لِلّٰهِ وَالصَّلَوَاتُ وَالطَّيِّبَاتُ، السَّلَامُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللّٰهِ وَبَرَكَاتُهُ، السَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اللّٰهِ الصَّالِحِينَ، أَشْهَدُ أَنْ لَا إِلٰهَ إِلَّا اللّٰهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ» ‘All verbal, physical, and bodily acts of worship are for Allah alone. O Prophet (peace and blessings be upon you)! May Allah’s peace, mercy, and blessings descend upon you. Peace be upon us and upon the righteous servants of Allah.’ When he says this phrase, it will include every righteous servant in the heavens and the earth. I bear witness that there is no deity except Allah and that Muhammad (peace and blessings be upon him) is His servant and His Messenger.”Then after this, he may supplicate for whatever he wishes.”

It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that once someone asked the Prophet (peace and blessings be upon him): "Which sin is the greatest?" The Prophet (peace and blessings be upon him) replied: "To associate someone with Allah, especially when it is Allah Who created you." The questioner asked: "After that, which sin is the greatest?" The Prophet (peace and blessings be upon him) said: "To kill your child out of fear that he will eat with you." The questioner asked: "After that?" He replied: "To commit adultery with your neighbor's wife." Sayyiduna Ibn Mas'ud (may Allah be pleased with him) says that Allah Almighty revealed this verse in confirmation of this: «‏‏‏‏﴿وَالَّذِينَ لَا يَدْعُونَ مَعَ اللّٰهِ إِلَهًا آخَرَ وَلَا يَقْتُلُونَ النَّفْسَ الَّتِي حَرَّمَ اللّٰهُ إِلَّا بِالْحَقِّ وَلَا يَزْنُونَ وَمَنْ يَفْعَلْ ذَلِكَ يَلْقَ أَثَامًا﴾» ‏‏‏‏ [الفرقان: 68] "And those who do not associate anyone with Allah, and do not kill a soul whom Allah has forbidden except by right, and do not commit adultery. Whoever does this shall meet a penalty."

It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that once some people asked: O Messenger of Allah (peace and blessings be upon him)! Will we be held accountable for the deeds of the time of ignorance? The Prophet (peace and blessings be upon him) said: "When you accept Islam and adopt good deeds, then you will not be held accountable for the deeds of the time of ignorance, but if you continue to do bad deeds after accepting Islam, then you will be held accountable for both the former and the latter."

Masruq (may Allah have mercy on him) says that once, in the main mosque, a man was saying that on the Day of Resurrection, a smoke will descend from the sky, it will take away the eyes and ears of the hypocrites, and it will enter the breaths of the Muslims causing a condition like cold. I went to Sayyiduna Ibn Mas'ud (may Allah be pleased with him) and told him this. He was sitting reclining, but upon hearing this, he sat up straight and said: O people! Whoever knows something well can speak about it, and whoever does not know something well should say that Allah knows best, because it is also a sign of a person's wisdom that he says "Allah knows best" about what he does not know. The revelation of the mentioned verse happened in this context: when the Quraysh exceeded all limits in disobeying the Prophet (peace be upon him), the Prophet (peace be upon him) prayed for a famine upon them like that in the time of Yusuf (peace be upon him). So, the Quraysh were surrounded by famine and difficulties, to the extent that they were forced to eat bones, and the situation became such that when anyone looked towards the sky, due to hunger, he would see smoke between himself and the sky. Upon this, Allah revealed this verse: «‏‏‏‏﴿فَارْتَقِبْ يَوْمَ تَأْتِي السَّمَاءُ بِدُخَانٍ مُبِينٍ o يَغْشَى النَّاسَ هَذَا عَذَابٌ أَلِيمٌ﴾» ‏‏‏‏ [الدخان: 10-11] "Wait for the Day when a clear smoke will come from the sky, which will envelop the people; this is a painful punishment." After this, some people came to the Prophet (peace be upon him) and said, "O Messenger of Allah (peace be upon him)! Pray for rain for Banu Mudar, they are perishing." So the Prophet (peace be upon him) prayed for them, and this verse was revealed: «‏‏‏‏﴿إِنَّا كَاشِفُو الْعَذَابِ قَلِيلًا﴾» ‏‏‏‏ [الدخان: 15] "We are removing the punishment from them." But when, after receiving prosperity, they returned to their previous actions, this verse was revealed: «‏‏‏‏﴿يَوْمَ نَبْطِشُ الْبَطْشَةَ الْكُبْرَى إِنَّا مُنْتَقِمُونَ﴾» ‏‏‏‏ [الدخان: 16] "On the Day We will seize them with a mighty grip, We will indeed take retribution." And this refers to the Battle of Badr. If it had been the Day of Resurrection, Allah would not have removed that punishment from them.

It is narrated from Sayyiduna Ibn Mas'ud (may Allah be pleased with him) that once I recited «‏‏‏‏﴿فَهَلْ مِنْ مُذَّكِرٍ﴾» ‏‏‏‏ with a "dhāl" in the presence of the Prophet (peace and blessings be upon him), so the Prophet (peace and blessings be upon him) said: "This word «﴿فَهَلْ مِنْ مُدَّكِرٍ﴾» [القمر: 40] is with a 'dāl'."