(17) باب الدُّعَاءِ فِي الصَّلاَةِ
Narrated `Aisha:
The Verse: 'Neither say your prayer aloud, nor say it in a low tone.' (17.110) was revealed as regards invocation.
Reference: Sahih al-Bukhari 6327
In-book reference: Book 80, Hadith 24
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 75, Hadith 339