בראשית, פרק י״ט, פסוק ו׳

Facing an angry and dangerous mob, Lot takes a calculated physical step to protect his guests. He places himself directly between the townspeople and the visitors inside his home by stepping out into the entranceway. To fully grasp his action, one must understand the physical space he navigates. An entrance is simply the empty void through which people pass, whereas a door is the solid physical object that swings on its hinges to seal a space shut [ביאור יש״ר, מחוקקי יהודה]. The very nature of a door relates to its function of either drawing people inside or rising up as a barrier to keep them out [קרני אור בשם אבן ג'נאח, רש״ר הירש].

By shutting the solid door behind him, Lot intends to stop the townspeople from forcing their way inside to seize his guests. The primary approach among commentators is that Lot himself pulled the door shut from the outside as he stepped into the crowd. However, another perspective suggests that someone remaining safely inside the house locked the door from within [רד״ק, ביאור יש״ר, ביאור שטיינזלץ].

This deliberate act of closing the door emphasizes the extreme and unique danger present in Sodom. The severity of the situation becomes clear when compared to a similar event involving a mob in Gibeah. In that incident, the host also went outside to plead with the crowd, but he left his door open. The mob in Gibeah was driven by wild desires that temporarily overpowered their minds, yet they still possessed a basic moral foundation that could be appealed to through reason. In Sodom, however, Lot knows he is confronting individuals motivated by absolute evil and murderous intent. Realizing that no moral reasoning will reach them, he is forced to physically and completely block all access to his home [מלבי״ם].