Narrated Aisha:Al Harith bin Hisham asked the Prophet, "How does the divine inspiration come to you?" He replied, "In all these ways: The Angel sometimes comes to me with a voice which resembles the sound of a ringing bell, and when this state abandons me, I remember what the Angel has said, and this type of Divine Inspiration is the hardest on me; and sometimes the Angel comes to me in the shape of a man and talks to me, and I understand and remember what he says."
حَدَّثَنَا فَرْوَةُ، حَدَّثَنَا عَلِيُّ بْنُ مُسْهِرٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ أَنَّ الْحَارِثَ بْنَ هِشَامٍ، سَأَلَ النَّبِيَّ صلى الله عليه وسلم كَيْفَ يَأْتِيكَ الْوَحْىُ قَالَ " كُلُّ ذَاكَ يَأْتِي الْمَلَكُ أَحْيَانًا فِي مِثْلِ صَلْصَلَةِ الْجَرَسِ، فَيَفْصِمُ عَنِّي وَقَدْ وَعَيْتُ مَا قَالَ، وَهْوَ أَشَدُّهُ عَلَىَّ، وَيَتَمَثَّلُ لِي الْمَلَكُ أَحْيَانًا رَجُلاً، فَيُكَلِّمُنِي فَأَعِي مَا يَقُولُ ".
Bukhari
Beginning of Creation • Hadith 26