Is it prescribed to praise Allah after burping and to seek refuge with Him after yawning?
Question

I noticed that some people ask Allah for forgiveness or praise Allah after burping. Is that Sunnah or is it an innovation (bid‘ah) that should be avoided?
Praise be to Allah.Firstly: 
Burping refers to the emission of air from the stomach with a sound via the mouth when one is full. 
There is nothing in the Sunnah to indicate that it is mustahabb for the Muslim, if he burps, to praise Allah or ask His forgiveness or remember Him with any dhikr. A man burped in the presence of the Prophet (blessings and peace of Allah be upon him) and he did not instruct him to say any kind of dhikr (remembering Allah, may He be exalted) after burping. 
At-Tirmidhi (2478) narrated – and classed the report as hasan – that Ibn ‘Umar said: A man burped in the presence of the Prophet (blessings and peace of Allah be upon him) and he said: “Keep your burps away from us, for the one who eats his fill the most in this world will be hungry for the longest time on the Day of Resurrection.” It was also classed as hasan by al-Albaani in Saheeh at-Tirmidhi.
Burping results from eating too much, and eating too much is regarded as blameworthy according to Islamic teaching. 
Al-Minnaawi (may Allah have mercy on him) said: That is because the one who eats too much will drink too much, then he will sleep too much, so his body will become lazy. End quote. 
At-Tayseer (1/312) 
The Messenger (blessings and peace of Allah be upon him) told that man not to burp in the presence of others, because this is offensive to them and is contrary to good manners, and he encouraged that man to eat less. 
But he did not encourage him to recite a particular dhikr, or instruct him to ask Allah for forgiveness or to do anything else, which indicates that reciting any dhikr after burping is not part of the Sunnah. 
Secondly: 
With regard to saying “al-hamdu Lillah (praise be to Allah)” after burping, it depends: 
1.
If a person says that, believing that it is Sunnah and is an act of worship that will bring him closer to Allah, then this comes under the heading of innovation, because he is seeking to draw close to Allah by means of something that He did not prescribe. 
2.
If he says that as a habit, without believing that it has any particular virtue, then this is not described as being either Sunnah or bid‘ah; rather it comes under the heading of permissible matters. 
3.
If he says it because of an idea that is established in his mind, which is that burping results from having eaten one’s fill, which is a blessing for which Allah deserves to be praised – and by the same token, if a person yawns and remembers that this yawning comes from the Shaytaan, so he seeks refuge with Allah from him, but he does not believe that this is prescribed as a Sunnah; rather he says it because of the idea that is established in his mind, 
Then in this case, it is more appropriate to say that there is nothing wrong with it. 
These details concerning these three scenarios are a summary of what our Shaykh, ‘Abd ar-Rahmaan al-Barraak (may Allah preserve him) told us after this question was put to him. 
Ibn Muflih said:
The one who burps does not have to respond with anything. So if he says, “Al-hamdu Lillah,” it may be said to him: “Hanee’an maree’an (May the food be delightful and pleasant for you)” or “Hanna’aka Allahu wa amraak (May Allah cause you to have the delight and pleasure of the food).” This was stated in ar-Ri‘aayah al-Kubra and by Ibn Tameem, and also by Ibn ‘Aqeel. And he said: We do not know of any Sunnah concerning that; rather it is a made-up custom.
End quote from al-Aadaab ash-Shar‘iyyah (2/346) 
Shaykh ‘Abd al-Muhsin al-‘Abbaad was asked: What is the ruling when one burps? 
He said: There is no report to indicate anything. But if a person praises Allah in all situations, and praises Him for having eaten his fill, which is one of the blessings of Allah, may He be glorified and exalted, there is nothing wrong with that. But if he believes that this is something that is prescribed in Islam in this situation, there is nothing to indicate that as far as I know.
End quote from Sharh Sunan Abi Dawood (492/19). 
Among the fatwas of the scholars, there is a fatwa on the issue of seeking refuge with Allah after yawning, which is similar to the case under discussion here. 
In Fataawa al-Lajnah ad-Daa’imah (2/320), in a fatwa issued by a committee under the leadership of Shaykh Ibn Baaz, it says: 
Seeking refuge with Allah after yawning was not mentioned in any report at all. Rather the individual should try to suppress yawning as much as he can, but if he seeks refuge with Allah from the Shaytaan when yawning, during prayer or otherwise, there is nothing wrong with that. End quote. 
Shaykh Ibn Baaz (may Allah have mercy on him) was asked: what is the ruling on seeking refuge with Allah when yawning? Is there any evidence concerning that? 
He said: There is nothing wrong with it, because yawning comes from the Shaytaan. But there is no report to indicate that doing so is mustahabb. However the Prophet (blessings and peace of Allah be upon him) told us that “yawning is from the Shaytaan, so if one of you feels the urge to yawn, let him suppress it as much as he can.” According to another version, “let him place his hand over his mouth.” This indicates that it is from the Shaytaan. 
If he says “A‘oodhu Billaahi min ash-Shaytaan ir-rajeem (I seek refuge with Allah from the accursed Shaytaan),” there is nothing wrong with that, but there is no report to this effect from the Prophet (blessings and peace of Allah be upon him). 
http://www.binbaz.org.sa/mat/9357
He also said: 
Many of the common folk do that because they know that this is from the Shaytaan, and that is why they do it. Otherwise, we do not know of anything in the Sunnah concerning that. Undoubtedly yawning is from the Shaytaan, and when a believer feels lazy, or when something harmful happens to him from the enemy of Allah, it is prescribed for him to seek refuge with Allah from the accursed Shaytaan, and to remember Allah a great deal, and to send blessings upon the Prophet (blessings and peace of Allah be upon him). But we do not know of any specific report concerning this issue. But if he seeks refuge with Allah from the Shaytaan when yawning because he knows that it is from the Shaytaan, there is nothing wrong with that. However, we do not say that it is Sunnah because there is no evidence to that effect. 
http://www.binbaz.org.sa/mat/9414
Shaykh ‘Abd al-Muhsin al-‘Abbaad said:
If a person seeks refuge with Allah from the Shaytaan on the grounds that yawning is from the Shaytaan, although he does not believe that this is a Sunnah of the Messenger of Allah (blessings and peace of Allah be upon him), then there is nothing wrong with that. But if he believes that this is Sunnah or thinks that it is prescribed for a person to say such and such when yawning, this is not correct. But if he remembers that yawning is from the Shaytaan, so he seeks refuge with Allah from the Shaytaan because of that, without believing that this is Sunnah, there is nothing wrong with that.
End quote from Sharh Sunan Abi Dawood (492/17)
And Allah knows best.