Assalaamu alaykum wa rahmatullaahi wa barakaatuhu, Shaykh. Is replying to the Salaam greeting by typing on a device, writing on a paper, or simply moving one's lips sufficient if one fears that a throat problem may become worse by speaking? I speak about emergency cases only, as I am having a sore throat and difficulty speaking these days, and it worsens when I speak, and at times I even undergo difficulty in the prayer or when recitating Quran. Please, advise, is it a must to speak and respond, or is what I mentioned above sufficient? Also, please advise regarding replying to certaing supplications, like the one related to sneezing and others, like when one says, 'may Allaah reward you'. May Allaah reward you, Shaykh.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.

One of the well-established rules of Islamic Fiqh is that 'difficulty entails facilitation'. This is because hardship must be eliminated in the Islamic Shariah; Allah, The Exalted, says (what means): {He has chosen you and has not placed upon you in the religion any difficulty.} [Quran 22:78]

Hence, if it is hard for you to return the greeting verbally, you are not obliged to do so. We could not find any statements for the scholars about the manner of returning the greeting in this case, and the same applies to the Tashmeet of (i.e. saying ‘yarhamuk Allah’ to) the sneezing person and thanking the one who has done us a favor and the like. However, we found statements about returning the greeting in particular by hand gestures when it is hard to verbalize it in certain situations.

‘Abdullah ibn ‘Umar, may Allah be pleased with him, reported, “The Messenger of Allah, sallallahu ‘alayhi wa sallam, went to Qubaa’ to offer the prayer. Then the Ansaar came to him and greeted him while he was in prayer. I asked Bilaal, ‘How did you see the Messenger of Allah, sallallahu ‘alayhi wa sallam, answer them when they greeted him while he was praying?’ He replied, ‘Like this,’ and he flexed his hand (with his palm facing the ground and the back of his hand facing the sky).” [Abu Daawood and At-Tirmithi]

Al-Haafith ibn Hajar wrote, “The forbiddance to greet by gesturing is confined to the person who is able to return the greetings physically (i.e. if is not unable to speak or a mute person, for instance) or is allowed to do so by the Shariah (i.e. if he is not in prayer, for instance, or answering the call of nature or the like); otherwise, it is permissible to return the greeting by making a gesture when the person is unable to return the greeting verbally, like when greeting a praying person, someone at a distance, or a mute person.” [Fat-h Al-Baari]

An-Nawawi cited the statement of the Shaafi‘i scholar Al-Mutawalli : “If one greeted a mute person and he greets him back with a hand gesture, the mute person has cleared himself of his liability from the religious obligation of returning the greeting because his hand gesture substitutes the verbal response.” [Al-Athkaar]

Returning the greeting silently by moving the lips only is not sufficient in this regard; the other person would not know if the greeted person has greeted him back or not; so it is better to combine the hand gesture with the lip movement.

We could not find any statements of the scholars about the other forms of returning the greetings that you mentioned, as we have already stated above.

Allah knows best.