Saying "Al-Hamdulillah" When Sneezing, Its Reply, and Manners Relating to Sneezing and Yawning

Abu Hurairah (May Allah be pleased with him) reported:
The Prophet ﷺ said, "When one of you sneezes he should say: 'Al-hamdu lillah (praise be to Allah),' and his brother or his companion should say to him: 'Yarhamuk-Allah (may Allah have mercy on you).' When he says this he should reply: 'Yahdikum-ullah wa yuslihu balakum (may Allah guide you and render sound your state of affairs)."'

[Al-Bukhari].

وعنه عن النبي ﷺ الله عليه وسلم الله عليه وسلم قال: "إذا عطس أحدكم فليقل: الحمد لله؛ وليقل له أخوه أو أصحابه: يرحمك الله، فإذا قال له: يرحمك الله، فليقل: يهديكم الله ويصلح بالكم" ((رواه البخاري)).

Abu Musa (May Allah be pleased with him) reported:
The Messenger of Allah ﷺ said, "When one of you sneezes and praises Allah (i.e., says Al-hamdu lillah), you should invoke Allah's Mercy upon him (i.e., say Yarhamuk-Allah), but if he does not praise Allah, you should not make a response." [Muslim].

وعن أبي موسي رضي الله عنه قال: سمعت رسول الله ﷺ يقول: "إذا عطس أحدكم فحمد الله فشمتوه، فإن لم يحمد الله فلا تشمتوه" ((رواه مسلم)).

Anas (May Allah be pleased with him) reported:
When two men sneezed in the presence of the Prophet ﷺ, he responded to one with "Yarhamuk-Allah (may Allah have mercy on you)" and did not respond to the other. The latter said to him: "You invoked a blessing on this man but did not do so in my case." The Prophet ﷺ replied, "He praised Allah (i.e., he said 'Al-hamdu lillah') but you did not."

[Al-Bukhari and Muslim].

وعن أنس رضي الله عنه قال: عطس رجلان عند النبي ﷺى الله عليه وسلم الله عليه وسلم ، فشمت أحدهما ولم يشمت الآخر، فقال الذي لم يشمته: عطس فلان فشمته، وعطست فلم تشمتني؟ فقال: "هذا حمد الله، وإنك لم تحمد الله" ((متفق عليه))

Abu Hurairah (May Allah be pleased with him) reported:
Whenever the Messenger of Allah ﷺ sneezed, he would cover his mouth with his hand or a piece of cloth, suppressing the sound this way.

[Abu Dawud and At-Tirmidhi].

وعن أبي هريرة رضي الله عنه قال: كان رسول الله ﷺ إذا عطس وضع يده أو ثوبه علي فيه، وخفض -أو غض- بها صوته. شك الراوي. ((رواه أبو داود، والترمذي وقال: حديث حسن صحيح)).

Abu Musa (May Allah be pleased with him) reported:
The Jews used to intentionally sneeze in the presence of the Messenger of Allah ﷺ hoping that he would say to them: 'Yarhamukum-ullah (may Allah have mercy on you),' but he would respond with: "Yahdikum-ullahu wa yuslihu balakum (may Allah guide you and render sound your state of affairs)."

[Abu Dawud and At- Tirmidhi].

وعن أبو موسي رضي الله عنه قال: كان اليهود يتعاطسون عند رسول الله ﷺ يرجون أن يقول لهم: يرحمكم الله، فيقول: ""يهديكم الله ويصلح بالكم" ((رواه أبو داود، والترمذي وقال: حديث حسن صحيح)).

Abu Sa'id Al-Khudri (May Allah be pleased with him) reported:
The Messenger of Allah ﷺ said, "When one yawns, he should put his hand over his mouth, otherwise the devil will enter."

[Muslim].

وعن أبي سعيد الخدري رضي الله عنه قال: قال رسول الله ﷺ : "إذا تثاءب أحدكم فليمسك بيده علي فيه، فإن الشيطان يدخل" ((رواه مسلم)).