✅Answer: Please pay attention to the following narrations:

1 عَنْ يُونُسَ عَنْ مُعَاوِيَةَ قَالَ: سَأَلْتُهُ عَنْ صَلَاةِ الْعِيدَيْنِ فَقَالَ رَكْعَتَانِ إِلَى أَنْ قَالَ وَ الْخُطْبَةُ بَعْدَ الصَّلَاةِ وَ إِنَّمَا أَحْدَثَ الْخُطْبَةَ قَبْلَ الصَّلَاةِ عُثْمَانُ وَ إِذَا خَطَبَ الْإِمَامُ فَلْيَقْعُدْ بَيْنَ الْخُطْبَتَيْنِ قَلِيلًا وَ يَنْبَغِي لِلْإِمَامِ أَنْ يَلْبَسَ يَوْمَ الْعِيدَيْنِ بُرْداً وَ يَعْتَمَّ شَاتِياً كَانَ أَوْ قَائِظاً الْحَدِيثَ.

📚Al-Kafi, Vol. 3, p. 460

Mu'awiyah ibn Ammar said: I asked the Imam (Sadiq) (peace be upon him) about the Eid al-Fitr and Eid al-Adha prayers; the Imam said: It is two rak'ahs... until he said: The sermon is after the prayer, and indeed, it was Uthman who innovated the sermon before the prayer, and when the Imam delivers the sermon, he should sit for a little between the two sermons, and it is proper for the Imam to wear a mantle and a turban on the day of Eid al-Fitr and Eid al-Adha, whether it is winter or summer!

2 عَنْ حَرِيزٍ عَنْ زُرَارَةَ عَنْ أَبِي عَبْدِ اللَّه قَالَ: قُلْتُ أَدْرَكْتُ الْإِمَامَ عَلَى الْخُطْبَةِ قَالَ: قَالَ تَجْلِسُ حَتَّى يَفْرُغَ مِنْ خُطْبَتِهِ ثُمَّ تَقُومُ فَتُصَلِّي قُلْتُ الْقَضَاءُ أَوَّلُ صَلَاتِي أَوْ آخِرُهَا قَالَ لَا بَلْ أَوَّلُهَا وَ لَيْسَ ذَلِكَ إِلَّا فِي هَذِهِ الصَّلَاةِ قُلْتُ فَمَا أَدْرَكْتُ مَعَ الْإِمَامِ مِنَ الْفَرِيضَةِ وَ مَا قَضَيْتُ قَالَ أَمَّا مَا أَدْرَكْتَ مِنَ الْفَرِيضَةِ فَهُوَ أَوَّلُ صَلَاتِكَ وَ مَا قَضَيْتَ فَآخِرُهَا.

📚Al-Tahdhib, Vol. 3, p. 136

Zurarah said: I said to Imam Sadiq (peace be upon him): I catch the Imam during the sermon (in the Eid al-Fitr and Eid al-Adha prayers). He said: You sit until he finishes his sermon and then you get up and pray.

I said: Was the beginning of my prayer missed or the end of it?! He said: Rather, the beginning! And this matter is not but in this very prayer (of Eid)!

I said: What about the amount of the obligatory (five-time) prayers that I catch with the congregational leader and what I make up? He said: The amount you catch is the beginning of your prayer, and what you make up is the end of your prayer!

✅Unlike the Friday prayer, in the Eid al-Fitr and Eid al-Adha prayers, the Eid prayer is first established and then the sermons are delivered by the Imam.

Now, if someone misses the Eid prayer and arrives during the sermons, he sits until the Imam finishes the sermon and then gets up and makes up the two rak'ahs of the Eid prayer.

✅Such a person has in fact caught the end of his prayer, which is the two sermons, and he makes up the beginning of his Eid prayer, which is those two rak'ahs, and this matter is exclusive to the Eid prayer!

But in the five-time prayers, if someone misses a part of the congregational prayer, the amount he prays with the Imam is considered the beginning of his prayer, and the amount he prays after the Imam gives the salam is considered as a makeup, and in fact, such a person has missed the end of his prayer!

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