Sahih al-Bukhari 124
صحيح البخاري#124SahihNarrated `Abdullah bin `Ammar:I saw the Prophet (ﷺ) near the Jamra and the people were asking him questions (about religious problems). A man asked, "O Allah's Messenger (ﷺ)! I have slaughtered the Hadi (animal) before doing the Rami." The Prophet (ﷺ) replied, "Do the Rami (now) and there is no harm." Another person asked, "O Allah's Messenger (ﷺ)! I got my head shaved before slaughtering the animal." The Prophet (ﷺ) replied, "Do the slaughtering (now) and there is no harm." So on that day, when the Prophet (ﷺ) was asked about anything as regards the ceremonies of Hajj performed before or after its due time his reply was, "Do it (now) and there is no harm
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 3:66