Sneezing And Yawning

It was narrated from Abu Hurairah (may Allah be pleased with him), that the Prophet(peace and blessings of Allah be upon him) said:
Allah likes sneezing and He dislikes yawning. If one of you sneezes and praises Allah, it is the duty of every Muslim who hears him to say to him:
Yarhamuk-Allah (may Allah have mercy on you)
As for yawning, it is from the Shaitan, so if one of you (feels the urge to) yawn, let him suppress it as much as he can, for when one of you yawns,the
Shaitan laughs at him. (Narrated by Al- Bukhari)
Ibn Hajar, may Allah have Mercy on him, said that Al-Khattabi said, What is meant by liking and disliking
here refers to the causes because sneezing is due to energy in the body, opening the pores and not eating too much, unlike yawning which is due to filling the body and making it heavy which stems from eating too much and mixing different types of food. The
former gives one energy for worship and the latter is the opposite.The Prophet ( peace and blessings of
Allah be upon him) , explained how to respond to one who sneezes, in the Hadith narrated by Abu Hurairah, may Allah be pleased with him, from the Prophet, (peace and blessings of Allahbe upon him) in which he said:
If one of you sneezes, let him say Alhamdu Lillah ( praise be to Allah), and let his brother or companion say to him, Yarhamuk-Allah (may Allah have mercy on you). If he says Yarhamuk-Allah (may Allah have
mercy on you) to him, let him say Yahdeekum Allahu wa yuslihu baalakum (may Allah guide you and
set your affairs straight).” (Al-Bukhari)
Nowadays doctors say that yawning is an indication that the brain and body need oxygen and food , and that the respiratory system has fallen short in supplying the oxygen needed by the brain and body. This happens when one is drowsy or unconscious and just before death. Yawning is a deep inhalation through the mouth, but the mouth is not the natural route for inhalation, because it is not equipped to purify the air as the nose is. If the mouth remains open while yawning, various kinds of germs, dust,
pollution and insects may enter with the inhaled breath and reach different parts of the body. Hence the Prophet,(peace and blessings of Allah be upon him), taught us to suppress yawning as
much as possible or to cover the mouth with the palm of the right hand or back of the left hand. Sneezing is the opposite of yawning, as it is powerful and sudden, and expels air forcefully from the lungs via
the nose and mouth,so it blows out whatever is in its way of dust, pollution, insects and germs that harps penetrated to the respiratory system. Hence, it is natural that sneezing should be from Allah because
of the benefits it brings to the body and that yawning should be from Satan because it is harmful to the body. Therefore it is many’s duty to praise Allah, the Exalted , for sneezing and seek refuge with Him from the accursed Satan when yawning.
(Al-Haqa’iq Al-Tibbiyah Fil-Islam)