From Sahih Bukhari (Hadith 7398):
Narrated `Aisha:The people said to the Prophet (ﷺ) , "O Allah's Messenger (ﷺ)! Here are people who have recently embraced Islam and they bring meat, and we do not know whether they had mentioned Allah's Name while slaughtering the animals or not." The Prophet (ﷺ) said, "You should mention Allah's Name and eat
Reference: Bukhari 7398