Sahih Muslim 2954

Abu Huraira reported Allah's Messenger (ﷺ) as saying:

The Last Hour would come (so sudden) that a person would be milking the she- camel and the (milk) would not reach the brim of the vessel that the Last Hour would come, and the two persons would be engaged in buying and selling of the clothes and their bargain would not be struck before the Last Hour would come. And someone would be setting his tank in order and he would have hardly set it right when the Last Hour would come.