The Prayer of the Two Eids
Man Lā Yaḥḍuruh al-Faqīh|Volume 1|Book 1|Chapter 79
وَ كَانَ عَلِيٌّ عَلَيْهِ اَلسَّلاَمُ يَأْكُلُ يَوْمَ اَلْفِطْرِ قَبْلَ أَنْ يَغْدُوَ إِلَى اَلْمُصَلَّى وَ لاَ يَأْكُلُ يَوْمَ اَلْأَضْحَى حَتَّى يَذْبَحَ.
Imam Ali عليه السلام would eat on the day of Eid al-Fitr before heading to the prayer area, but on the day of Eid al-Adha, he would not eat until after performing the ritual sacrifice.
- Ṣaḥīḥ al-Faqīh