[Machine] Bilal used to perform the call to prayer when the sun set, but he would not establish the prayer until he saw the Prophet Muhammad ﷺ . Then, when he saw him, he would proceed to establish the prayer.  

كَانَ بِلَالٌ يُؤَذِّنُ إِذَا دَحَضَتِ الشَّمْسُ ثُمَّ لَا يُقِيمُ حَتَّى يَرَى النَّبِيَّ ﷺ فَإِذَا رَآهُ أَقَامَ حِينَ يَرَاهُ  

I came to the Prophet ﷺ with some men from my tribe and stayed with him for twenty nights. He was kind and merciful to us. When he realized our longing for our families, he said to us, "Go back and stay with your families and teach them the religion, and offer the prayer and one of you should pronounce the Adhan for the prayer when its time is due and the oldest one amongst you should lead the prayer." (Using translation from Bukhārī 628)   

أَتَيْتُ النَّبِيَّ ﷺ فِي نَفَرٍ مِنْ قَوْمِي فَأَقَمْنَا عِنْدَهُ عِشْرِينَ لَيْلَةً وَكَانَ رَحِيمًا رَقِيقًا فَلَمَّا رَأَى شَوْقَنَا إِلَى أَهْلِنَا قَالَ ارْجِعُوا فَكُونُوا فِيهِمْ وَعَلِّمُوهُمْ وَصَلُّوا فَإِذَا حَضَرَتِ الصَّلَاةُ فَلْيُؤَذِّنْ لَكُمْ أَحَدُكُمْ وَلْيَؤُمَّكُمْ أَكْبَرُكُمْ  

[Machine] Malik said, "The Fajr prayer is being called before dawn, and as for the other prayers, we have not seen them being called except after their prescribed time has come."  

قَالَ مَالِكٌ لَمْ يَزَلِ الصُّبْحُ يُنَادَى بِهَا قَبْلَ الْفَجْرِ فَأَمَّا غَيْرُهَا مِنَ الصَّلَوَاتِ فَإِنَّا لَمْ نَرَهَا يُنَادَى بِهَا إِلَّا بَعْدَ أَنْ يَحِلَّ وَقْتُهَا  

[Machine] Imam Al-Shafi'i said, "The adhan (call to prayer) is not to be called for any prayer other than Fajr (dawn prayer) except after its designated time, because I did not know of anyone who narrated that the Prophet ﷺ called the adhan for a prayer before its time, other than Fajr. And we have not seen the Mu'adhdhins (callers of adhan) among us calling the adhan except after the entry of its time, except for Fajr."  

قَالَ الشَّافِعِيُّ لَا يُؤَذَّنُ لِصَلَاةٍ غَيْرِ الصُّبْحِ إِلَّا بَعْدَ وَقْتِهَا لِأَنِّي لَمْ أَعْلَمْ أَحَدًا حَكَى عَنْ رَسُولِ اللهِ ﷺ أَنَّهُ أَذَّنَ لِصَلَاةٍ قَبْلَ وَقْتِهَا غَيْرَ الْفَجْرِ وَلَمْ نَرَ الْمُؤَذِّنِينَ عِنْدَنَا يُؤَذِّنُونَ إِلَّا بَعْدَ دُخُولِ وَقْتِهَا إِلَّا الْفَجْرَ