The Prophet ﷺ used to slaughter his sacrificial animal at the prayer ground, and Ibn Umar would do the same.
حدثنا عثمان بن أبي شيبة أن أبا أسامة حدثهم عن أسامة عن نافع
أن النبي ﷺ كان يذبح أضحيته بالمصلى وكان ابن عمر يفعله
[Sahih] Ibn Majah narrated it in the chapter on sacrifices, section "Slaughtering at the Prayer Place," hadith 3161, from the narration of Usama bin Zayd through this same route, and its chain is hasan. Its basis is found in Bukhari, hadith 982, from the narration of Nafi.