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.
Hadith 2628
It is narrated from Sayyiduna Zaid bin Khalid Al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace be upon him) said: "Jibreel (peace be upon him) came and said: 'O Muhammad (peace be upon him), command your companions to recite the Talbiyah aloud, for this is the symbol of Hajj.'"
Hadith 2629
Sayyiduna Zaid bin Khalid Juhani رضي الله عنه narrates that the Messenger of Allah صلى الله عليه وسلم said: “Jibreel عليه السلام came to me and said, ‘Make Talbiyah your slogan because Talbiyah is the slogan of Hajj.’” Imam Abu Bakr رحمه الله says that these words, “Talbiyah is the slogan of Hajj,” belong to the same category about which I have already explained that the Arabs say, “This is the best deed,” and by this they mean that this deed is among the best of deeds. Sometimes the Arabs say, “The best deed is such and such,” and by this they mean that this deed is one of the better deeds among the best deeds. Similarly, the statement of the Noble Prophet صلى الله عليه وسلم: “Talbiyah is the slogan of Hajj,” means that Talbiyah is one of the slogans of Hajj.
Hadith 2630
Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace be upon him) said: "Jibreel (peace be upon him) ordered me to recite the Talbiyah aloud because it is one of the symbols of Hajj." Imam Abu Bakr (may Allah have mercy on him) says that I have mentioned the chains of this hadith in Kitab al-Kabir.