وَسُئِلَ مَالِك ، عَنِ النِّدَاءِ يَوْمَ الْجُمُعَةِ هَلْ يَكُونُ قَبْلَ أَنْ يَحِلَّ الْوَقْتُ؟ فَقَالَ: لَا يَكُونُ إِلَّا بَعْدَ أَنْ تَزُولَ الشَّمْسُ
Imam Malik (may Allah have mercy on him) was asked: Is it permissible to give the adhan for Jumu'ah before its time? He replied: No! Not until the sun has declined.