Ummul Momineen Sayyidina Ayesha radiyallahu anha reports that the The Messenger of Allah (Sallallahu alaihi wasallam) said:
"The son of Adam does not perform any actions on the day of
sacrifice which is more pleasing to Allah than the shedding of blood.
The sacrificed animal shall come on the Day of judgment
with its horns, hair, and hooves (to be weighed).
The sacrifice is accepted by Allah before the blood reaches the ground.
Therefore sacrifice with an open and happy heart.
(Tirmizi, Ibne Majah)