The Messenger of Allah ﷺ sacrificed two white rams with black markings.
أخبرنا محمد بن المثنى عن خالد قال حدثنا حميد عن ثابت
ضحى رسول الله ﷺ بكبشين أملحين
No references are available.
[Sahih] Ahmad narrated it (3/178) from the hadith of Humayd Tawil, with the same wording. It is also found in Kubra, hadith no. 4476. The hadith has many corroborating narrations, including the previous hadith.