Az-Zumar 56

أَن تَقُولَ نَفْسٌ يَـٰحَسْرَتَىٰ عَلَىٰ مَا فَرَّطتُ فِى جَنۢبِ ٱللَّهِ وَإِن كُنتُ لَمِنَ ٱلسَّـٰخِرِينَ

an taqūla nafsun yāḥasratā ʿalā mā farraṭtu fī janbi l-lahi wa-in kuntu lamina l-sākhirīna

Lest a soul should say, "Oh, [how great is] my regret over what I neglected in regard to Allāh and that I was among the mockers."