Narrated by Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: The one who takes back a gift is like a person who starts licking his own vomit. Imam Qatadah said: In my opinion, vomit is forbidden.
Hadith Takhrij«أخرجه البخاري: 2621، ومسلم: 16222 ، (انظر مسند أحمد ترقيم الرسالة: 2646 ترقیم بيت الأفكار الدولية: 2646»
Brief Explanation
Benefits: … There is no such evidence that indicates the prohibition or impurity of vomit; in reality, the matter is being stated by observing the disposition of a person of sound nature. It is correct that there is no evidence for the prohibition or impurity of vomit, but to take back a gift after giving it is prohibited, as is made clear from Hadith 6290.