Surah Al-Mulk, Verse 13

وَأَسِرُّواْ قَوۡلَكُمۡ أَوِ ٱجۡهَرُواْ بِهِۦٓۖ إِنَّهُۥ عَلِيمُۢ بِذَاتِ ٱلصُّدُورِ١٣

wa-asirrū qawlakum awi ij'harū bihi innahu ʿalīmun bidhāti l-ṣudūri

And conceal your speech or publicize it; indeed, He is Knowing of that within the breasts.