I heard the Messenger of Allah ﷺ say, "No man approaches his client asking him for some surplus he has, only for him to withhold it, except that on the Day of Resurrection a serpent will be summoned to him, licking its lips, made from the surplus he withheld."
حدثنا يحيى بن سعيد
سمعت رسول الله ﷺ يقول لا يأتي رجل مولى له يسأله من فضل عنده فيمنعه إلا دعي له يوم القيامة شجاع يتلمظ فضله الذي منع