6:81
وَكَيْفَ أَخَافُ مَآ أَشْرَكْتُمْ وَلَا تَخَافُونَ أَنَّكُمْ أَشْرَكْتُم بِٱللَّهِ مَا لَمْ يُنَزِّلْ بِهِۦ عَلَيْكُمْ سُلْطَٰنًۭا ۚ فَأَىُّ ٱلْفَرِيقَيْنِ أَحَقُّ بِٱلْأَمْنِ ۖ إِن كُنتُمْ تَعْلَمُونَ
And how should I fear what you associate while you do not fear that you have associated with Allah that for which He has not sent down to you any authority? So which of the two parties has more right to security, if you should know?
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
أَتُحَاجُّونِّى فِى اللَّهِ وَقَدْ هَدَانِى
(Do you dispute with me about Allah while He has guided me). The Ayah means, do you argue with me about Allah, other than Whom there is no god worthy of worship, while He has guided me to the Truth and made me aware of it Therefore, how can I ever consider your misguided statements and false doubts Ibrahim said next,
وَلاَ أَخَافُ مَا تُشْرِكُونَ بِهِ إِلاَّ أَن يَشَآءَ رَبِّى شَيْئاً
(and I fear not those whom you associate with Allah in worship. (Nothing can happen to me) except when my Lord wills something.) Ibrahim said, among the proofs to the falsehood of your creed, is that these false gods that you worship do not bring about any effect, and I do not fear them or care about them. Therefore, if these gods are able to cause harm, then use them against me and do not give me respite. Ibrahim's statement,
إِلاَّ أَن يَشَآءَ رَبِّى شَيْئاً
(except when my Lord wills something.) means, only Allah causes benefit or harm.