Silence

It is narrated from Makhul (may Allah have mercy on him) that the Messenger of Allah (peace and blessings be upon him) said to Sayyiduna Mu'adh (may Allah be pleased with him) in a hadith: "As long as you remain silent, you will remain safe and secure (from every kind of harm); but when you speak, that speech of yours will either be in your favour (a cause of reward) or against you (a cause of reckoning and harm)."
Imam Abu Dawud recorded this hadith. This narration is mursal in its chain, because Makhul (may Allah have mercy on him) is a Tabi'i and he narrated it directly from the Prophet (peace and blessings be upon him); however, its meaning concerning guarding the tongue is fully in agreement with other authentic and reliable hadith.

It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that he said: "Adopting silence is pure wisdom, but those who act upon it are very few."
Imam Abu Ya'la narrated this hadith in his Musnad. The narrator in its chain, Uthman bin Sa'd al-Katib, is da'if (weak); therefore this narration is weak in its chain, although its meaning is established by other authentic hadith and reports.

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever is pleased to remain safe (from trials and sins), let him make silence binding upon himself."
Because of the weakness of a narrator in its chain named Uthman bin Abd al-Rahman, this narration is weak in its chain; however, the meaning of adopting silence and attaining salvation through it is established by other authentic hadith.

Abd al-Rahman bin Abdullah (may Allah have mercy on him) narrates from his father, Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), that he said by way of advice: "O my dear son! Let your house suffice you (that is, in a time of trials, value the seclusion of the home), shed tears (of remorse) over your sins, and keep your tongue under control."
And the hadith of Sayyiduna Abu Dharr (may Allah be pleased with him) on this subject is mentioned at the very beginning of the hadith on the noble Prophets (peace and blessings be upon them).

Muslim bin Abdullah bin Sabrah narrates from his father (Sayyiduna Abdullah bin Sabrah (may Allah be pleased with him)) that the Messenger of Allah (peace and blessings be upon him) said: "I forbid you three things: idle talk and passing on hearsay here and there without verification, needlessly wasting wealth and property, and asking many questions."
Imam al-Bukhari (may Allah have mercy on him) transmitted this narration in his book al-Tarikh through the route of Qays bin Hafs from Mu'tamir, and Ibn al-Sakan (may Allah have mercy on him) says: I do not know any other narration from the Companion of the Messenger, Sayyiduna Abdullah bin Sabrah (may Allah be pleased with him), besides this one.

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Indeed, a man utters some word merely to make the people around him laugh, while (in its harm and destructiveness) that word falls even farther than the distance of (the vast plain of) Ukaz, and he does not even realise its destructiveness."
Ibn Abi Umar narrated this hadith from al-Hanafi, and Husayn al-Ju'fi from Za'idah, both through the route of al-Hajari with this same chain.

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that Sayyidah Aishah al-Siddiqah (may Allah be pleased with her) said: I heard the Messenger of Allah (peace and blessings be upon him) while he was addressing the people; he (peace and blessings be upon him) was saying: "Whoever guards what is between his two jaws (that is, the tongue) and guards what is between his two legs (that is, the private parts), he will enter Paradise."
Imam Abu Ya'la al-Mawsili recorded this hadith in his Musnad, and other authentic narrations on this subject are found in the books of hadith.

Iqal bin Shabbah narrates from his father, he from his grandfather, and he from his father (the Companion) (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said to him: "Guard the organ that is between your two jaws (that is, the tongue) and what is between your two legs (that is, the private parts)." He (the Companion) says: (Hearing this comprehensive advice) I stood up from there saying: This is sufficient for me.
Imam al-Tabarani recorded this hadith in al-Mu'jam al-Kabir (7338). Although there is criticism of its chain because of some narrators, its meaning is established by other authentic hadith, such as Sahih al-Bukhari (6474), in which Paradise is guaranteed for the one who guards his tongue and private parts.