Sahih Muslim , Hadith 1093

Ibn Mas'ud (Allah be pleased with him) reported Allah's Messenger as saying The Adhan of Bilal should not restrain anyone among you from eating Sahur (last meal before daybreak during the month of Ramadan) for he announces Adhan (or he calls) at (the fag end of) the night to make him turn who stands for prayer among you, and to awaken those who are sleeping among you. And he said: The dawn is not like it, as one says (and he lifted his hand) till he (dispersed his fingers) and said: It is like this.

حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا إِسْمَاعِيلُ بْنُ إِبْرَاهِيمَ، عَنْ سُلَيْمَانَ التَّيْمِيِّ، عَنْ أَبِي، عُثْمَانَ عَنِ ابْنِ مَسْعُودٍ، - رضى الله عنه - قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لاَ يَمْنَعَنَّ أَحَدًا مِنْكُمْ أَذَانُ بِلاَلٍ - أَوْ قَالَ نِدَاءُ بِلاَلٍ - مِنْ سَحُورِهِ فَإِنَّهُ يُؤَذِّنُ - أَوْ قَالَ يُنَادِي - بِلَيْلٍ لِيَرْجِعَ قَائِمَكُمْ وَيُوقِظَ نَائِمَكُمْ ‏"‏ ‏.‏ وَقَالَ ‏"‏ لَيْسَ أَنْ يَقُولَ هَكَذَا وَهَكَذَا - وَصَوَّبَ يَدَهُ وَرَفَعَهَا - حَتَّى يَقُولَ هَكَذَا ‏"‏ ‏.‏ وَفَرَّجَ بَيْنَ إِصْبَعَيْهِ ‏.‏

sunnah.com

This hadith has been narrated by Sulaiman al-Taimi with the same chain of transmitters (but with a slight variation of words) that he (the Holy Prophet) said: The dawn is not like it as it is said; he then gathered his fingers and lowered them. But he said, it is like this (and he placed the index finger upon the other one and spread his hand).

حَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا أَبُو خَالِدٍ، - يَعْنِي الأَحْمَرَ - عَنْ سُلَيْمَانَ التَّيْمِيِّ، بِهَذَا الإِسْنَادِ غَيْرَ أَنَّهُ قَالَ ‏"‏ إِنَّ الْفَجْرَ لَيْسَ الَّذِي يَقُولُ هَكَذَا ‏"‏ ‏.‏ وَجَمَعَ أَصَابِعَهُ ثُمَّ نَكَسَهَا إِلَى الأَرْضِ ‏"‏ وَلَكِنِ الَّذِي يَقُولُ هَكَذَا ‏"‏ ‏.‏ وَوَضَعَ الْمُسَبِّحَةَ عَلَى الْمُسَبِّحَةِ وَمَدَّ يَدَيْهِ ‏.‏

sunnah.com

This hadith has been narrated on the authority of Sulaiman Taimi with the same chain of transmitters and, at the end, it was said that the first Adhan was meant to awaken those who were in slumber amongst them and in order to make them turn who stand in (prayer) among them (towards food at the commencement of the fast). Jarir (one of the narrators) said that the Messenger did not say like this but he said like it (true dawn) that the streaks of (true dawn ) are horizontal and not vertical.

وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا مُعْتَمِرُ بْنُ سُلَيْمَانَ، ح وَحَدَّثَنَا إِسْحَاقُ بْنُ، إِبْرَاهِيمَ أَخْبَرَنَا جَرِيرٌ، وَالْمُعْتَمِرُ بْنُ سُلَيْمَانَ، كِلاَهُمَا عَنْ سُلَيْمَانَ التَّيْمِيِّ، بِهَذَا الإِسْنَادِ ‏.‏ وَانْتَهَى حَدِيثُ الْمُعْتَمِرِ عِنْدَ قَوْلِهِ ‏"‏ يُنَبِّهُ نَائِمَكُمْ وَيَرْجِعُ قَائِمَكُمْ ‏"‏ ‏.‏ وَقَالَ إِسْحَاقُ قَالَ جَرِيرٌ فِي حَدِيثِهِ ‏"‏ وَلَيْسَ أَنْ يَقُولَ هَكَذَا وَلَكِنْ يَقُولُ هَكَذَا ‏"‏ ‏.‏ يَعْنِي الْفَجْرَ هُوَ الْمُعْتَرِضُ وَلَيْسَ بِالْمُسْتَطِيلِ ‏.‏

sunnah.com