Jamieson, Fausset and Brown on Mark 1:32

32. And at even, when the sun did set--so Mt 8:16. Luke (Lu 4:40) says it was setting.

they brought unto him all that were diseased, and them that were possessed with devils--the demonized. From Lu 13:14 we see how unlawful they would have deemed it to bring their sick to Jesus for a cure during the sabbath hours. They waited, therefore, till these were over, and then brought them in crowds. Our Lord afterwards took repeated occasion to teach the people by example, even at the risk of His own life, how superstitious a straining of the sabbath rest this was.