Chapter on Sacrificial Offerings
Man Lā Yaḥḍuruh al-Faqīh|Volume 2|Book 3|Chapter 136
رَوَى سُوَيْدٌ اَلْقَلاَّءُ عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ عَنْ أَبِي جَعْفَرٍ عَلَيْهِ اَلسَّلاَمُ قَالَ: «اَلْأُضْحِيَّةُ وَاجِبَةٌ عَلَى مَنْ وَجَدَ مِنْ صَغِيرٍ أَوْ كَبِيرٍ وَ هِيَ سُنَّةٌ.
It is narrated from Suwayd al-Qallāʾ, from Muhammad ibn Muslim, from Imam Abu Jaʿfar عليه السلام, who said: "The sacrifice (udhiyya) is obligatory upon anyone who can afford it, whether young or old, and it is also a sunnah."
- Ṣaḥīḥ al-Faqīh, p. 173