Ash-Shama'il Al-Muhammadiyah, Book 43, Hadith 300 (English) ⓘ

'Abdullah bin Abi Qays Radiyallahu 'Anhu reports: "I inquired from 'Aayeshah Radiyallahu 'Anha about the recital of Rasulullah Sallallahu 'Alayhi Wasallam, did he 'recite softly or audibly? She replied: 'He recited in both ways'. I said: 'Alhamdulillaah, (Praise be to, Allah), who has accorded us easiness in the matter"'. (According to the situation whatever was proper, reciting softly or audibly was adopted)

حَدَّثَنَا قُتَيْبَةُ، قَالَ‏:‏ حَدَّثَنَا اللَّيْثُ، عَنْ مُعَاوِيَةَ بْنِ صَالِحٍ، عَنْ عَبْدِ اللهِ بْنِ أَبِي قَيْسٍ، قَالَ‏:‏ سَأَلْتُ عَائِشَةَ، عَنْ قِرَاءَةِ النَّبِيِّ صلى الله عليه وسلم أَكَانَ يُسِرُّ بِالْقِرَاءَةِ أَمْ يَجْهَرُ‏؟‏ قَالَتْ‏:‏ كُلُّ ذَلِكَ قَدْ كَانَ يَفْعَلُ قَدْ كَانَ رُبَّمَا أَسَرَّ وَرُبَّمَا جَهَرَ فَقُلْتُ‏:‏ الْحَمْدُ لِلَّهِ، الَّذِي جَعَلَ فِي الأَمْرِ سَعَةً‏.‏