Genesis 19:1

Two angels came to Sedom at the evening; and Lot sat in the gate of Sedom. And Lot saw, and rose up to meet them from the gate of the tabernacle. And he bowed his face to the ground,

ויבאו שני המלאכים סדומה בערב, even though they arrived at that city without “time” having elapsed since they departed from Avraham, (compare Berachot 4 the angel Gavriel needing two steps, and the angel Michael only one step) they remained outside the city gates, invisible, not entering and appearing to Lot until evening. The same is true of 18,22 וילכו סדומה. Avraham had concluded his dialogue with G’d already some time previously.

ויקם לקראתם, in order to prevent them from spending the night in the street. This was customary also in cities other than Sodom when no one had offered shelter to unexpected strangers. In such instances there was always the danger that the strangers would be harmed by some of the residents of the city.

וישתחו אפים ארצה, they clearly looked sufficiently imposing to warrant being treated deferentially.

ויבאו שני המלאכים, these were the two who had previously been described as שני האנשים, “the two men.” When next to Avraham, they did not outrank him; therefore the Torah did not accord them the title “angels.” When compared to Lot, they outclassed him spiritually so much that they could not be described as אנשים, men. (Bereshit Rabbah, 50,2)

וירא לוט ויקם לקראתם, he had learned the virtue of welcoming guests while he had been with Avraham.

ויבואו שני המלאכים סדומה בערב, “two of the angels arrived in Sodom in the evening;” when Lot saw them, he asked them for the purpose of their visit. They told him that it was their mission to destroy the city. The reason why they volunteered this information was that they said to themselves that if they were simply to order him to leave town with their families without giving them a plausible reason, they would simply ignore them. But, since they had taken it upon themselves to reveal something G–d had not intended to be revealed at that time, they were punished by Him, by being exiled from the celestial regions for 138 years. This was in spite of the fact that what they had done had been well intentioned. Angels are subject to penalties even for committing “minor” errors by not having checked with their Master first, relying on the superior wisdom with which they had been endowed. This superior knowledge enables them to know what goes on in the minds of human beings. We find another example of punishment as warnings for celestial creatures where Mattatron, G–d’s “general manager” for running the universe on His behalf, was punished as stated in the Talmud tractate Chagigah, folio 15. This angel was expelled (temporarily) from the celestial regions and punished with sixty fiery strokes, in order to warn him not to fall victim to the same error as Elisha ben Avuyah on earth, who had arrived at the conclusion that Satan is an independent force in the universe rather than also a messenger carrying out missions on behalf of his Divine master. Rabbi Yehudah hachassid said that angels are punished with sixty lashes whereas human beings are not punished by more than forty (39) lashes, is that on earth already thirteen year olds qualify for such punishment, whereas such punishments are inflicted on over twenty year olds in the celestial regions. Just as 39 lashes on earth are three times thirteen so sixty is three times twenty.