Muwatta Imam Malik Book of Hajj, Hadith 251

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."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عِيسَى بْنِ طَلْحَةَ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرِو بْنِ الْعَاصِ، أَنَّهُ قَالَ وَقَفَ رَسُولُ اللَّهِ ﷺ لِلنَّاسِ بِمِنًى وَالنَّاسُ يَسْأَلُونَهُ فَجَاءَهُ رَجُلٌ فَقَالَ لَهُ يَا رَسُولَ اللَّهِ لَمْ أَشْعُرْ فَحَلَقْتُ قَبْلَ أَنْ أَنْحَرَ . فَقَالَ رَسُولُ اللَّهِ ﷺ " انْحَرْ وَلاَ حَرَجَ " . ثُمَّ جَاءَهُ آخَرُ فَقَالَ يَا رَسُولَ اللَّهِ لَمْ أَشْعُرْ فَنَحَرْتُ قَبْلَ أَنْ أَرْمِيَ قَالَ " ارْمِ وَلاَ حَرَجَ " . قَالَ فَمَا سُئِلَ رَسُولُ اللَّهِ ﷺ عَنْ شَىْءٍ قُدِّمَ وَلاَ أُخِّرَ إِلاَّ قَالَ " افْعَلْ وَلاَ حَرَجَ " .