When the knife is placed on the throat of the sacrificial animals, at the same time we should be placing a knife over the throats of our evil desires.
When evil desires enter our hearts and the knife is placed over them the blood is going to flow and a pain experienced. The horizon of the heart is going to turn red with the blood of our evil desires just as the horizon turns red before the sun comes out. Thereafter we will find the sun of the love of Allah subhaanahu wataala rising within the heart.
We do not wish to sacrifice the evil desires of our hearts. Instead what we do is give a bit in charity, perform a Qurbani and leave it at that. Ibraaheem alayhis salaam was prepared to place the knife over the throat of his son while we cannot sacrifice our Haraam (Impermissible) desires. There is nothing but harm in Haraam which is spelt with double a so making it double harmful. There is no goodness in Haraam. It brings nothing but restlessness, anxiety and problems.
From Short Inspirational Audio of Shaykh Yunus Patel (Rahimahullaah)