Allah tells us about when the angels came to Lut in the form of young men with handsome faces. When they entered his home, he said:
("Verily, you are people unknown to me." They said: "Nay, we have come to you with that (torment) which they have been doubting.") meaning that they were bringing the punishment and destruction that the people doubted they would ever suffer from.
(And we have brought you the truth) is like the Ayah,
(We do not send the angels down except with the truth) 15:8 and
(and certainly, we tell the truth.) They said this in affirmation of the news that they brought him, that he would be saved and his people would be destroyed.