Ibn Umar, may Allah be pleased with him, narrates that the Messenger of Allah, peace and blessings be upon him, said: "A believer is not one who curses." In another narration: "It is not appropriate for a believer to be one who curses." Its chain is good; narrated by al-Tirmidhi.

Samurah bin Jundub (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Do not say to one another: 'May Allah's curse be upon you,' 'May Allah's wrath be upon you,' or 'Go to Hell.'" And in another narration: "Do not even say: 'Go into the (Hell) Fire.'" Its chain is weak. Narrated by al-Tirmidhi and Abu Dawood.

Abu Darda (may Allah be pleased with him) narrates: I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: "When a servant sends a curse upon something, the curse rises towards the sky, but before it reaches, the gates of the sky are closed. Then it descends towards the earth, and its gates are also closed. Then it turns to the right and to the left, and when it finds no way, it returns to the one upon whom the curse was sent, provided he is deserving of it; otherwise, it returns to the one who uttered it." Its chain is weak. Narrated by Abu Dawood.

It is narrated from Ibn Abbas (may Allah be pleased with him) that the wind blew away a man's sheet, so he cursed it. The Messenger of Allah (peace and blessings be upon him) said: "Do not curse it, for it is only following orders. And whoever sends a curse upon something that does not deserve it, the curse returns upon him." Its chain is weak. Narrated by al-Tirmidhi and Abu Dawood.

Ibn Mas'ud (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Let none of my companions convey to me anything (displeasing) about another companion, for I like that when I come to you, my heart is clean." Its chain is weak. Narrated by Abu Dawood.

Aisha (may Allah be pleased with her) narrated: I said to the Prophet (peace and blessings be upon him): "It is enough for you regarding Safiyyah (peace and blessings be upon her) that she is such and such," meaning that she is short in stature. The Prophet (peace and blessings be upon him) said: "You have uttered a word which, if mixed with the sea, would overwhelm it (i.e., it would change its nature)." Its chain is authentic. Narrated by Ahmad, al-Tirmidhi, and Abu Dawood.

Anas (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Obscenity in anything makes it defective, and modesty in anything adorns it." Its chain is authentic, narrated by al-Tirmidhi.

Khalid bin Ma'dan narrates from Mu'adh (may Allah be pleased with him), who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever reproaches his (Muslim) brother for a (past) sin, then this person will commit that (sin) before he dies." This refers to the sin from which he has already repented. (Tirmidhi) And he said: This hadith is gharib, its chain is not connected because Khalid did not meet Mu'adh bin Jabal (may Allah be pleased with him). Its chain is weak. Narrated by al-Tirmidhi.

Wathilah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Do not express joy at your (Muslim) brother's affliction, for it is possible that Allah may have mercy on him and test you with that (affliction)." Tirmidhi, and he said: This hadith is Hasan Gharib. Its chain is weak. Narrated by al-Tirmidhi.

Aisha (may Allah be pleased with her) narrates that the Prophet (peace and blessings be upon him) said: "I do not like to imitate anyone, even if I were given such and such wealth." Tirmidhi has narrated it and declared it authentic. Its chain is authentic, narrated by Tirmidhi.