(Hood) 11 : 70
فَلَمَّا رَأَىٰ أَيْدِيَهُمْ لَا تَصِلُ إِلَيْهِ نَكِرَهُمْ وَأَوْجَسَ مِنْهُمْ خِيفَةً ۚ قَالُوا لَا تَخَفْ إِنَّا أُرْسِلْنَا إِلَىٰ قَوْمِ لُوطٍ

Thus when he saw their hands were not stretched for it, he distrusted them and felt anxiety about them; they said: “You don’t fear, indeed we have been sent to the people of Looth”.

When the guests did not eat the food, Ibrahim feared they might be Angels, who are often assigned to execute punishment, even though they had brought him the glad news about Ishaaq. If the people of a Messenger become wrongdoers, transgressors, and Mujirims after being warned by Adhikr, they are destroyed, as explained in verse 10:73. It is stated in verse 51:32: “The Angels said, ‘Indeed, we have been sent to a people who are Mujirims.’” The people of Looth were Mujirims who engaged in sodomy, robbery, and other mischievous deeds. See explanation  2:168-169 and 6:47.