[Machine] I heard my father say that the meaning of the Prophet's ﷺ saying, "The Mu'adhdhins will have the longest necks on the Day of Judgment" does not mean that their necks will physically elongate. Rather, it is because people will be thirsty on the Day of Judgment and when a person becomes thirsty, their necks will retract, while the Mu'adhdhins will not be thirsty, so their necks will remain erect.  

سَمِعْتُ أَبِي يَقُولُ مَعْنَى قَوْلِ النَّبِيِّ ﷺ الْمُؤَذِّنُونَ أَطْوَلُ النَّاسِ أَعْنَاقًا يَوْمَ الْقِيَامَةِ لَيْسَ أَنَّ أَعْنَاقَهُمْ تَطُولُ وَذَلِكَ إِنَّ النَّاسَ يَعْطَشُونَ يَوْمَ الْقِيَامَةِ فَإِذَا عَطِشَ الْإِنْسَانُ انْطَوَتْ عُنُقُهُ وَالْمُؤَذِّنُونُ لَا يَعْطَشُونَ فَأَعْنَاقُهُمْ قَائِمَةٌ