Al Kahf, 104 Ayah
18:104
ٱلَّذِينَ ضَلَّ سَعۡيُهُمۡ فِي ٱلۡحَيَوٰةِ ٱلدُّنۡيَا وَهُمۡ يَحۡسَبُونَ أَنَّهُمۡ يُحۡسِنُونَ صُنۡعًا ١٠٤
Al-Ladhīna Đalla Sa`yuhum Fī Al-Ĥayāati Ad-Dunyā Wa Hum Yaĥsabūna 'Annahum Yuĥsinūna Şun`āan
[They are] those whose effort is lost in worldly life, while they think that they are doing well in work."