The Prophet ﷺ said, "Whoever buys a musarrah has the option, after milking it, of returning it along with a saa of dates if he wishes."
حدثنا أبو كريب حدثنا وكيع عن حماد بن سلمة عن محمد بن زياد
قال النبي ﷺ من اشترى مصراة فهو بالخيار إذا حلبها إن شاء ردها ورد معها صاعا من تمر
[Its isnad is sahih]. Ahmad also narrated it, 2/386, from the hadith of Hammad bin Salama with the same wording. It has other routes in Bukhari, no. 2148, and Muslim, no. 1515, and others, from Abu Hurairah .There is also a narration on this subject from Anas [Bazzar (Kashf Astar), 22/89, 90, no. 1274, and Abu Yaala, 5/155, no. 2767, and Bayhaqi, 5/319], and from a man among the companions of the Prophet ﷺ [Ahmad, 4/314].