Yahya related to me from Malik from Ibn Shihab from clsa ibn Talha that Abdullah ibn Amr ibn al-As said, "The Messenger of Allah (ﷺ) stopped for the people at Mina, and they questioned him and a man came and said to him, 'Messenger of Allah, I was unclear about what to do and I shaved before sacrificing,' and the Messenger of Allah (ﷺ) said, 'Sacrifice, and don't worry.' Then another came to him and said 'Messenger of Allah, I was unclear about what to do and I sacrificed before throwing the stones.' He advised, 'Throw, and don't worry.' "
Amr continued, saying that the Messenger of Allah (ﷺ) was not asked about anything done before or after without his saying, "Do it, and don't worry."