If there are many travellers, Adhan and Iqama should be pronounced, (the same is to be observed) in ‘Arafat and Al-Muzdalifa too

Narrated Abu Dhar:

We were in the company of the Prophet on a journey and the Mu'adhdhin wanted to pronounce the Adhan for the (Zuhr) prayer. The Prophet ﷺ said to him, "Let it become cooler." Then he again wanted to pronounce the Adhan but the Prophet;
said to him, "Let it become cooler." The Mu'adh-dhin again wanted to pronounce the Adhan for the prayer but the Prophet ﷺ said, "Let it become cooler," till the shadows of the hillocks become equal to their sizes. The Prophet added, "The severity of the heat is from the raging of Hell."

حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنِ الْمُهَاجِرِ أَبِي الْحَسَنِ، عَنْ زَيْدِ بْنِ وَهْبٍ، عَنْ أَبِي ذَرٍّ، قَالَ كُنَّا مَعَ النَّبِيِّ ﷺ فِي سَفَرٍ فَأَرَادَ الْمُؤَذِّنُ أَنْ يُؤَذِّنَ فَقَالَ لَهُ " أَبْرِدْ ". ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ فَقَالَ لَهُ " أَبْرِدْ ". ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ. فَقَالَ لَهُ " أَبْرِدْ ". حَتَّى سَاوَى الظِّلُّ التُّلُولَ فَقَالَ النَّبِيُّ ﷺ {إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ}

Narrated Malik bin Huwairth:

Two men came to the Prophet with the intention of a journey. The Prophet ﷺ said, "When (both of) you set out, pronounce Adhan and then Iqama and the oldest of you should lead the prayer."

حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ أَبِي قِلاَبَةَ، عَنْ مَالِكِ بْنِ الْحُوَيْرِثِ، قَالَ أَتَى رَجُلاَنِ النَّبِيَّ ﷺ يُرِيدَانِ السَّفَرَ فَقَالَ النَّبِيُّ ﷺ " إِذَا أَنْتُمَا خَرَجْتُمَا فَأَذِّنَا ثُمَّ أَقِيمَا ثُمَّ لِيَؤُمَّكُمَا أَكْبَرُكُمَا ".

Narrated Malik:

We came to the Prophet and stayed with him for twenty days and nights. We were all young and of about the same age. The Prophet was very kind and merciful. When he realized our longing for our families, he asked about our homes and the people there and we told him. Then he asked us to go back to our families and stay with them and teach them (the religion) and to order them to do good things. He also mentioned some other things which I have (remembered or) forgotten. The Prophet then added, "Pray as you have seen me praying and when it is the time for the prayer one of you should pronounce the Adhan and the oldest of you should lead the prayer.

حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا عَبْدُ الْوَهَّابِ، قَالَ حَدَّثَنَا أَيُّوبُ، عَنْ أَبِي قِلاَبَةَ، قَالَ حَدَّثَنَا مَالِكٌ، أَتَيْنَا إِلَى النَّبِيِّ ﷺ وَنَحْنُ شَبَبَةٌ مُتَقَارِبُونَ، فَأَقَمْنَا عِنْدَهُ عِشْرِينَ يَوْمًا وَلَيْلَةً، وَكَانَ رَسُولُ اللَّهِ ﷺ رَحِيمًا رَفِيقًا، فَلَمَّا ظَنَّ أَنَّا قَدِ اشْتَهَيْنَا أَهْلَنَا أَوْ قَدِ اشْتَقْنَا سَأَلَنَا عَمَّنْ تَرَكْنَا بَعْدَنَا فَأَخْبَرْنَاهُ قَالَ " ارْجِعُوا إِلَى أَهْلِيكُمْ فَأَقِيمُوا فِيهِمْ وَعَلِّمُوهُمْ وَمُرُوهُمْ ـ وَذَكَرَ أَشْيَاءَ أَحْفَظُهَا أَوْ لاَ أَحْفَظُهَا ـ وَصَلُّوا كَمَا رَأَيْتُمُونِي أُصَلِّي، فَإِذَا حَضَرَتِ الصَّلاَةُ فَلْيُؤَذِّنْ لَكُمْ أَحَدُكُمْ وَلْيَؤُمَّكُمْ أَكْبَرُكُمْ ".

Narrated Nafi:

Once in a cold night, Ibn 'Umar pronounced the Adhan for the prayer at ,Dajnan (the name of a mountain) and then said, "Pray at your homes", and informed us that Allah's Apostle used to tell the Mu'adhdin to pronounce Adhan and say, "Pray at your homes" at the end of the Adhan on a rainy or a very cold night during the journey."

حَدَّثَنَا مُسَدَّدٌ، قَالَ أَخْبَرَنَا يَحْيَى، عَنْ عُبَيْدِ اللَّهِ بْنِ عُمَرَ، قَالَ حَدَّثَنِي نَافِعٌ، قَالَ أَذَّنَ ابْنُ عُمَرَ فِي لَيْلَةٍ بَارِدَةٍ بِضَجْنَانَ ثُمَّ قَالَ صَلُّوا فِي رِحَالِكُمْ، فَأَخْبَرَنَا أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ يَأْمُرُ مُؤَذِّنًا يُؤَذِّنُ، ثُمَّ يَقُولُ عَلَى إِثْرِهِ، أَلاَ صَلُّوا فِي الرِّحَالِ. فِي اللَّيْلَةِ الْبَارِدَةِ أَوِ الْمَطِيرَةِ فِي السَّفَرِ.