Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: Quraysh asked the Messenger of Allah (peace and blessings be upon him) for permission regarding the 'atirah (the sacrifice of Rajab), saying: "O Messenger of Allah, we used to offer the 'atirah in Rajab." The Messenger of Allah (peace and blessings be upon him) said to them: "An 'atirah like the 'atirah of the Days of Ignorance? Rather, whoever among you wishes to slaughter for Allah, eat (from it) and give in charity, let him do so." Their 'atirah was that they would slaughter, then go to the blood of their slaughtered animals and smear it on the heads of their idols.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11536