that the Messenger of Allah (ﷺ) said: "There are six things due from the believer to another believer: Visiting him when he is ill, attending (his funeral) to him when he dies, accepting his invitation when he invites, giving him Salam when he meets him, replying to him when he sneezes, and wishing him well when he is absent and when he is present."

that the Messenger of Allah (ﷺ) said: "When one of you sneezes let him say: 'Al-Hamdulillahi 'Ala Kulli Hal (All praise is due to Allah in every circumstance).' And let the one replying to him say: "Yarhamukallah (May Allah have mercy upon you).' And let him say to him: 'Yahdikumullah Wa Yuslihu Balakum (May Allah guide you and rectify your affairs).'"

that two men sneezed in the presence of the Prophet (ﷺ); he responded to one of them and did not respond to the other. The one who was not responded to said: "O Messenger of Allah! You responded to this person and did not respond to me?' So the Messenger of Allah (ﷺ) said: "He praised Allah while you did not praise Him."

Shu'bah reported this Hadith from 'Ikrimah bin 'Ammar and it is similar to the narration of Yahya bin Sa'eed. (A chain to support that).

from his mother, from her father, who said: "The Messenger of Allah (ﷺ) said: 'Reply three times to the sneezing person. If he (sneezes) more, then if you wish reply and if you do not then do not.'"

that the Messenger of Allah (ﷺ) said: "Let one of you not have his brother stand from his seat then sit in it."

that the Messenger of Allah (ﷺ) said: "Let one of you not have his brother stand from his seat then sit in it."

that the Messenger of Allah (ﷺ) said: "A man has more right to his seat. If he leaves for some need of his, then he returns, then he has more right to his seat."

"The Prophet (ﷺ) would pare, or take from his mustache, and Ibrahim Khalilur-Rahman would do it (as well)."

that the Messenger of Allah (ﷺ) said: "Trim the mustache and leave the beard to grow."

"I saw the Prophet (ﷺ) reclining upon a pillow."

that the Messenger of Allah (ﷺ) said: "There are six courtesies due from a Muslim to another Muslim: To give Salam to him when he meets him, to accept his invitation when he invites him, to reply to him when he sneezes, to visit him when he is ill, to follow his funeral when he dies, and to love for him what he loves for himself."

(Another chain) from 'Ali from the Prophet (ﷺ) with similar meaning.

from his father: "A man sneezed in the presence of the Messenger of Allah (ﷺ) while I was present, so the Messenger of Allah (ﷺ) said: 'Yarhamukallah (May Allah have mercy upon you).' Then he sneezed a second and third time. So the Messenger of Allah (ﷺ) said: "This man is suffering from a cold.'"

"You are suffering from a cold." (A chain to support that)

that the Messenger of Allah (ﷺ) said: "The sneeze is from Allah and the yawn is from Ash-Shaitan. So when one of you yawns let him cover his mouth with his hand. For when he says 'Ah, Ah' Ash-Shaitan laughs from inside his opening." [And indeed Allah loves the sneeze and He dislikes the Yawn, so when a man says Ah, Ah when yawning, indeed Ash-Shaitan laughs from inside his opening."]

that the Messenger of Allah (ﷺ) said: "It is not lawful for a man to separate two people except with their permission."

that the Messenger of Allah (ﷺ) said: "Five are from the Fitrah: Cutting the pubic hair, circumcision, paring the mustache, plucking the under arm hair and trimming the fingernails."

that the Prophet (ﷺ) said: "Ten are from the Fitrah: Paring the mustache, leaving the beard to grow, Siwak, cleaning the nose with water, paring the fingernails, washing the knuckles, plucking the underarm hair, shaving the pubic hairs, and Intiqas with water."