Mishkat al-Masabih
Abu Huraira said that the Prophet’s recitation at night was partly in a loud voice and partly in a low voice. Abu Dawud transmitted it.
وَعَن أبي هُرَيْرَة قَالَ: كَانَ قِرَاءَةُ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ بِاللَّيْلِ يَرْفَعُ طَوْرًا وَيَخْفِضُ طَوْرًا. رَوَاهُ أَبُو دَاوُدَ
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