صحيح ابن خزيمه
Sahih Ibn Khuzaymah
كتاب: المناسكBook of Rituals (Hajj/Umrah)
(100) بَابُ الْبَيَانِ أَنَّ رَفْعَ الصَّوْتِ بِالْإِهْلَالِ مِنْ شِعَارِ الْحَجِّ،100 Subchapter: Raising the voice with the intention is a sign of Hajj
Hadith Q2628
وَإِنَّمَا أُمِرَ الْمُهِلُّ بِرَفْعِ الصَّوْتِ بِهِ إِذْ هُوَ مِنْ شِعَارِ الْحَجِّ.
The person reciting the Talbiyah has been commanded to proclaim the Talbiyah aloud for this very reason, because it is a symbol of Hajj.
