إِنَّا تَطَيَّرْنَا بِكُمْ

(For us, we see an evil omen from you;) meaning, `we do not see in your faces any sign of good for our lives.' Qatadah said, "They were saying, `if something bad befalls us, it will be because of you."' Mujahid said, "They were saying: People like you never enter a town, but its people are punished."

لَئِن لَّمْ تَنتَهُواْ لَنَرْجُمَنَّكُمْ

The sense of the statement: قَالُوا طَائِرُ‌كُم مَّعَكُمْ (They said, "Your bad omen deeds.' The word: طَایٔر (ta'ir) essentially denotes bad omen or misfortune and, on occasions, it is also used to refer to the effects of misfortune, that is, wretchedness. Here, this is what it means. (Ibn Kathir, Qurtubi)