[But whatever they may say or do,] repel the evil [which they commit] with something that is better: We are fully aware of what they attribute [to Us].

Repel evil with that which is best: We are well acquainted with the things they say.

Repel evil with that which is better. We are Best Aware of that which they allege.

Repel evil with that which is best. We know best what they describe.

Repel, by [means of] what is best, [their] evil. We are most knowing of what they describe.