A.T. Robertson Commentary Mark 1:33

"And all the city was gathered together at the door." — Mark 1:33 (ASV)

At the door (προς την θυραν). At the door of Peter's house. The whole city was gathered together there (n episun gmen , past perfect passive periphrastic indicative, double compound επ and συν). Mark alone mentions this vivid detail. He is seeing with Peter's eyes again. Peter no doubt watched the beautiful scene with pride and gratitude as Jesus stood in the door and healed the great crowds in the glory of that sunset. He loved to tell it afterwards.

Divers diseases (ποικιλαις νοσοις). See Mt 4:24 about ποικιλος meaning many-coloured, variegated. All sorts of sick folk came and were healed.