Just wanted to clarify, is it a fact that those who don't respond to the Athan will not be able to say the Kalimah on their deathbed?
There is no authenticated Hadith on this. What I found said that repeating after the adhan is not even obligatory.
The scholars differed concerning the ruling on repeating after the muezzin and repeating the words of the adhaan. The correct view – which is the view of the majority of scholars – is that repeating it is mustahabb, not obligatory. This is the view of the Maalikis, Shaafa’is and Hanbalis.
Al-Nawawi (may Allaah have mercy on him) said in al-Majmoo’ (3/127):
Our view is that repeating (the words of the adhaan) is Sunnah, not obligatory. This is the view of the majority of scholars. Al-Tahhaawi narrated that some of the salaf held a different view and said that it is obligatory.
In al-Mughni (1/256) it is narrated that Imam Ahmad said: If he does not repeat his words there is nothing wrong with that.
This is indicated by the words of the Prophet (peace and blessings of Allaah be upon him) to Maalik ibn al-Huwayrith and those who were with him: “When the time for prayer comes, let one of you give the adhaan and let the oldest of you lead you in prayer.”
This indicates that repeating the words of the adhaan is not obligatory. This conclusion is based on the fact that the Prophet (peace and blessings of Allaah be upon him) was teaching them, and in this case there was a need to explain everything they needed to know. This delegation of people may not have had any knowledge of what the Prophet (peace and blessings of Allaah be upon him) said about repeating the words of the adhaan, and the fact that the Prophet (peace and blessings of Allaah be upon him) did not mention it, even though there may have been a need to explain it to them, and this delegation stayed with him for twenty days then left, indicates that repeating the words of the adhaan is not obligatory. This is the most correct view. End quote from al-Sharh al-Mumti’ (2/75).
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