Virtues of Qurbaani

Qurbaani is a practice commanded by Allah:

... So turn in prayer towards your Lord and Sacrifice (animals). (108:2)

Aaishah radhiyallahu anhaa narrates that Rasulullah sallallahu alayhi wasallam said: "There is nothing dearer to Allah during the days of  Qurbaani than the sacrificing of animals. The sacrificed animal shall  come on the Day of Judgement 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 pp. 275 Vol.1) (Ibne Maajah pp. 226 Vol.1)

Zayd Ibne Arqam radhiyallahu anhu relates that the Companions  radhiyallahu annum asked: "O Rasulullah (sallallahu alayhi wasallam)! What is Qurbaani?" He  replied, "It is the Sunnah of your father Ibraaheem alayhis Salaam."
They asked again: “What benefit do we get out from it?" He  answered: "A reward for every hair (of the sacrificed animal)." "And  (what reward is there for animals with) wool, O
Rasulullah (sallallahu alayhi wasallam)?" they  asked. "A reward", he said, "for every fiber of the wool."

(Ibne Maajah pp. 226) (Mishkaat pp. 129)

When a person slaughters a Qurbaani animal, he is forgiven at the fall of the first drop of blood, and verily, the animal shall be brought forward on the Day Of Judgement with its blood, meat etc., and shall be increased in weight seventy times more than its own weight, and thereafter it will be placed on the scale of deeds.

(Kanz)

On Whom is Qurbaani Waajib?