“I heard the Messenger of Allah (ﷺ) say: ‘By the One in Whose hand is my soul, were it not for the fact that there are some believing men who would not feel happy to stay behind (when I go out on a campaign) and I do not have the means to provide them with mounts (so that they cn join me), I would not have stayed behind from any campaign or battle in the cause of Allah. By the One in Whose hand is my soul, I wish that I could be killed in the cause of Allah, then brought back to life, then be killed, then be brought back to life, then be killed then be brought back to life, then be killed.'”
“Whoever among you sees the new crescent of Dhul-Hijjah and wants to offer a sacrifice, let him not take anything from his hair or nails.”
It was narrated from Anas bin Malik that a man slaughtered on the Day of Sacrifice, (meaning) before the ‘Eid prayer, and the Prophet (ﷺ) ordered him to do it again.