Once, during a tour in Kosala with a large number of monks, the Buddha saw a fisherman selling fish.
Sitting down at the foot of a tree by the wayside, the Buddha pointed out to the monks how no fisherman enjoyed a happy life because his mind was always engaged in slaughter.
It was the same, he said, with those who killed other creatures; those guilty of killing would suffer greatly after death. A.iii.301 f.