The prior verse stated that he couldn’t go back to the larger towns for some time, but Jesus did eventually go back into town, but almost immediately, the crowds began to gather. (Q: What were the large and small Galilean towns?)
The time prior to his return to Capernaum is unspecified beyond it having been some multiple of days, so maybe just a few days or maybe a few weeks. Also, in the Greek, they hear he was not in the house, but whose house it is isn’t specified, which means that it would either be Jesus’ house, or the house of one of Peter, perhaps. It’s also not specified exactly who is there in the house with him. If he’s been dutifully collecting members of his house, then it could all just be “his people”, but there are clues about who these people were.
In one sense, these verses are a continuation of the authority brag. He’s got a magnetic personality that attracts inordinate hoards: people stop their work, leave their homes, and gather together for the opportunity to hear him speak or just to see his face. Even if he hasn’t been around for several days, folks come running when they hear of his proximity. The people are there to hear and obey.