✅ Answer: Please consider the following narrations:

1⃣عَنْ سُلَیْمَانَ بْنِ جَعْفَرٍ قَالَ: سَأَلْتُ أَبَا الْحَسَنِ عَنِ التَّلْبِیَةِ وَ عِلَّتِهَا فَقَالَ إِنَّ النَّاسَ إِذَا أَحْرَمُوا نَادَاهُمُ اللَّهُ تَعَالَی ذِکْرُهُ فَقَالَ یَا عِبَادِی وَ إِمَائِی لَأُحَرِّمَنَّکُمْ عَلَی النَّارِ کَمَا أَحْرَمْتُمْ لِی فَقَوْلُهُمْ لَبَّیْکَ اللَّهُمَّ لَبَّیْکَ إِجَابَةٌ لِلَّهِ عَزَّ وَ جَلَّ عَلَی نِدَائِهِ لَهُمْ.

📚 Al-Faqih, Vol. 2, p. 196

Sulaiman bin Ja'far said: I asked Imam Abu al-Hasan (peace be upon him) about the Talbiyah and its reason. The Imam said: When people enter into the state of Ihram, Allah Almighty calls them and says: 'O My servants and maidservants! I forbid you from the fire, just as you have become forbidden to Me.' Therefore, when they say: 'Labbayk Allahumma Labbayk,' it is their response to the divine call!

2⃣قَالَ أَمِیرُالْمُؤْمِنِینَ جَاءَ جَبْرَئِیلُ إِلَی النَّبِیِّ فَقَالَ لَهُ إِنَّ التَّلْبِیَةَ شِعَارُ الْمُحْرِمِ فَارْفَعْ صَوْتَکَ بِالتَّلْبِیَةِ لَبَّیْکَ اللَّهُمَّ لَبَّیْکَ لَبَّیْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ إِنَّ الْحَمْدَ وَ النِّعْمَةَ لَکَ وَ الْمُلْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ.

📚 Al-Faqih, Vol. 2, p. 326

Amir al-Mu'minin (peace be upon him) said: Jibril came to the Messenger of Allah (peace be upon him) and said: 'Indeed, the Talbiyah is the symbol of the Muhrim. So raise your voice with the Talbiyah:'

لَبَّیْکَ اللَّهُمَّ لَبَّیْکَ لَبَّیْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ إِنَّ الْحَمْدَ وَ النِّعْمَةَ لَکَ وَ الْمُلْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ

3⃣ Imam Sadiq (peace be upon him) said: The Talbiyah is as follows:

لَبَّیْکَ اللَّهُمَّ لَبَّیْکَ لَبَّیْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ إِنَّ الْحَمْدَ وَ النِّعْمَةَ لَکَ وَ الْمُلْکَ لَا شَرِیکَ لَکَ لَبَّیْکَ ذَا الْمَعَارِجِ لَبَّیْکَ لَبَّیْکَ دَاعِیاً إِلَی دَارِ السَّلَامِ لَبَّیْکَ لَبَّیْکَ غَفَّارَ الذُّنُوبِ لَبَّیْکَ لَبَّیْکَ أَهْلَ التَّلْبِیَةِ لَبَّیْکَ لَبَّیْکَ ذَا الْجَلَالِ وَ الْإِکْرَامِ لَبَّیْکَ لَبَّیْکَ مَرْهُوباً وَ مَرْغُوباً إِلَیْکَ لَبَّیْکَ لَبَّیْکَ تُبْدِئُ وَ الْمَعَادُ إِلَیْکَ لَبَّیْکَ لَبَّیْکَ کَشَّافَ الْکُرَبِ الْعِظَامِ لَبَّیْکَ لَبَّیْکَ عَبْدُکَ وَ ابْنُ عَبْدَیْکَ لَبَّیْکَ لَبَّیْکَ یَا کَرِیمُ لَبَّیْکَ

Say it after every obligatory and voluntary prayer, when your camel lifts you, when you ascend a height, when you descend into a valley, when you meet someone on horseback, when you wake up from your sleep, and at dawn. Say it as much as you can, and say it loudly. If you miss some of these forms of Talbiyah, it will not harm you, but it is better to complete it.

And know that the four essential phrases of Talbiyah that begin the words are necessary, and it is obligatory; it is the Oneness of Allah, and the sent Prophets said the same. Frequently say 'Labbayk Dhā al-Ma'arij Labbayk,' because the Messenger of Allah (peace be upon him) used to say it frequently. The first person to say the Talbiyah was Prophet Ibrahim (peace be upon him)...

📚 Al-Kafi, Vol. 4, p. 335

4⃣عَنِ ابْنِ فَضَّالٍ عَنْ رِجَالٍ شَتَّی عَنْ أَبِی جَعْفَرٍ قَالَ: قَالَ رَسُولُ اللَّهِ مَنْ لَبَّی فِی إِحْرَامِهِ سَبْعِینَ مَرَّةً إِیمَاناً وَ احْتِسَاباً أَشْهَدَ اللَّهُ لَهُ أَلْفَ أَلْفِ مَلَکٍ بِبَرَاءَةٍ مِنَ النَّارِ وَ بَرَاءَةٍ مِنَ النِّفَاقِ.

📚 Al-Kafi, Vol. 4, p. 337

Imam Baqir (peace be upon him) said: The Messenger of Allah (peace be upon him) said: 'Anyone who, with faith and expectation of reward, says the Talbiyah seventy times while in Ihram, Allah will testify with one million angels for their absolution from the fire and their freedom from hypocrisy!'

5⃣عَنْ فَضَالَةَ بْنِ أَیُّوبَ عَمَّنْ حَدَّثَهُ عَنْ أَبِی عَبْدِ اللَّه قَالَ: إِنَّ اللَّهَ وَضَعَ عَنِ النِّسَاءِ أَرْبَعاً الْجَهْرَ بِالتَّلْبِیَةِ وَ السَّعْیَ بَیْنَ الصَّفَا وَ الْمَرْوَةِ وَ دُخُولَ الْکَعْبَةِ وَ الِاسْتِلَامَ.

📚 Al-Tahdhīb, Vol. 5, p. 93

Imam Sadiq (peace be upon him) said: 'Indeed, Allah has removed four things from women: raising the voice with Talbiyah, running between Safa and Marwah, entering the Ka'bah, and touching (or kissing) the Black Stone.'

✅ Based on the above narrations and others, the obligatory Talbiyah is what has been mentioned in narration 2⃣, and the more complete version found in narration 3⃣ is better. Men should say it loudly, while women are not required to raise their voice.

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْر