✅Answer: Pay attention to the following narrations:

1 عَنْ حَمَّادِ بْنِ عِيسَى عَنْ زُرَارَةَ قَالَ: قَالَ أَبُو جَعْفَرٍ قَالَ رَسُولُ اللَّهِ السُّجُودُ عَلَى سَبْعَةِ أَعْظُمٍ الْجَبْهَةِ وَ الْيَدَيْنِ وَ الرُّكْبَتَيْنِ وَ الْإِبْهَامَيْنِ مِنَ الرِّجْلَيْنِ وَ تُرْغِمُ بِأَنْفِكَ إِرْغَاماً أَمَّا الْفَرْضُ فَهَذِهِ السَّبْعَةُ وَ أَمَّا الْإِرْغَامُ بِالْأَنْفِ فَسُنَّةٌ مِنَ النَّبِيِّ

📚 Al-Tahdhib, vol. 2, p. 299

📚 Al-Istibsar, vol. 1, p. 327

Translation: Imam Baqir (peace and blessings of Allah be upon him) said: 'The Messenger of Allah (peace and blessings of Allah be upon him) said: 'Prostration is on seven bones: the forehead, the two palms, the two knees, and the two big toes. And you also touch your nose to the ground. But the obligatory part is these seven, and touching the nose to the ground is a tradition of the Prophet (peace and blessings of Allah be upon him).'

2 عَنْ مُحَمَّدِ بْنِ يَحْيَى عَنْ عَمَّارٍ عَنْ جَعْفَرٍ عَنْ أَبِيهِ قَالَ: قَالَ عَلِيٌّ لَا تُجْزِي صَلَاةٌ لَا يُصِيبُ الْأَنْفُ مَا يُصِيبُ الْجَبِينُ.

📚 Al-Tahdhib, vol. 2, p. 298

📚 Al-Istibsar, vol. 1, p. 327

Translation: Imam Baqir (peace and blessings of Allah be upon him) said: 'Ali (peace and blessings of Allah be upon him) said: 'A prayer in which the nose does not touch what the forehead touches is not sufficient.'

3 عَنْ عَبْدِ اللَّهِ بْنِ الْمُغِيرَةِ عَمَّنْ سَمِعَ أَبَا عَبْدِ اللَّهِ يَقُولُ لَا صَلَاةَ لِمَنْ لَمْ يُصِبْ أَنْفُهُ مَا يُصِيبُ جَبِينُهُ.

📚 Al-Kafi, vol. 3, p. 333

Translation: Imam Sadiq (peace and blessings of Allah be upon him) said: 'There is no prayer for one who does not touch his nose to the place where he touches his forehead.'

4 عن الصادق فی حدیث الحماد.... وَ سَجَدَ عَلَى ثَمَانِيَةِ أَعْظُمٍ الْجَبْهَةِ وَ الْكَفَّيْنِ وَ عَيْنَيِ الرُّكْبَتَيْنِ وَ أَنَامِلِ إِبْهَامَيِ الرِّجْلَيْنِ وَ الْأَنْفِ فَهَذِهِ السَّبْعَةُ فَرْضٌ وَ وَضْعُ الْأَنْفِ عَلَى الْأَرْضِ سُنَّةٌ وَ هُوَ الْإِرْغَامُ....

📚 Faqih, vol. 1, p. 300

Translation: Hammad ibn 'Isa says in describing the prayer of Imam Sadiq (peace and blessings of Allah be upon him): '...and the Imam prostrated on eight bones: the forehead, the two palms, the two knee springs, the two big toes, and the nose. The seven are the obligatory part, and placing the nose on the ground is a tradition and that is 'irgham.'

5 عَنْ مُحَمَّدِ بْنِ مُصَادِفٍ قَالَ سَمِعْتُ أَبَا عَبْدِ اللَّهِ يَقُولُ إِنَّمَا السُّجُودُ عَلَى الْجَبْهَةِ وَ لَيْسَ عَلَى الْأَنْفِ سُجُودٌ.

📚 Al-Tahdhib, vol. 2, p. 298

📚 Al-Istibsar, vol. 1, p. 326

Translation: Muhammad ibn Musaddif (or Mudharib) said: 'I heard Imam Sadiq (peace and blessings of Allah be upon him) saying: 'Indeed, prostration is on the forehead, and there is no prostration on the nose.'

✅As is clear from the above narrations, the obligatory part of prostration is on seven points, which are: the forehead, the two palms, the two knees, and the two big toes.

Also, the Ahl al-Bayt (peace be upon them) have stated and practiced placing the nose on the same thing the forehead is placed on as a tradition of the Messenger of Allah (peace and blessings of Allah be upon him), and they have named it 'irgham,' meaning sticking the nose to the 'ragham,' which is the ground. And regarding it, they have said the above hadiths, which are presented to the readers without any further explanation for them to use. In other words, touching the nose to the same thing the forehead touches is a tradition of the Messenger of Allah (peace and blessings of Allah be upon him), and regarding it, the Ahl al-Bayt (peace be upon them) have said the above hadiths, and the intensity of its importance is that in hadith 3, they have said about one who omits it: 'There is no prayer for him!'

اللَّهُمَّ فَصَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ