Hūd

فَلَمَّا رَءَآ أَيْدِيَهُمْ لاَ تَصِلُ إِلَيْهِ نَكِرَهُمْ وَأَوْجَسَ مِنْهُمْ خِيفَةً قَالُوا لا تَخَفْ إِنَّآ اُرْسِلْنَآ إِلَي قَوْمِ لُوطٍ

70. “But when he saw their hands extended not towards it, he mistrusted them, and conceived a fear of them. They said: ‘Fear not; we have been sent against the people of Lot’.”

Abraham’s (as) fear is different from the kind of fear and weakness found in ordinary men when facing problematic situations, for he was the archetypical iconoclast in history who was never afraid of anything. Nevertheless focusing one’s attention on possible dangers and on being a possible target is another matter. The verse says:

“But when he saw their hands extended not towards it, he mistrusted them, and conceived a fear of them. They said: ‘Fear not; we have been sent against the people of Lot’.”

At any rate, since Lot (as) and his tribe was one of the groups under Abraham’s command, he had to be briefed before their annihilation.