43-Surah Az-Zukhruf ( The Gold Adornment ) 89
So turn aside from them and say, ‘ Peace.’ But they are going to know.
فَاصْفَحْ عَنْهُمْ وَقُلْ سَلَامٌ ۚ فَسَوْفَ يَعْلَمُونَ
Quran's Tafhim ( explanation)
*71) That is, "You should neither curse them for their scornful words and attitude of mockery and derision, nor respond with harsh words: just wish them well and take your leave."