Al-Buhuti reported: Umar, may Allah be pleased with him, said, “O Allah, show me the truth as truth and guide me to follow it. Show me the false as false and guide me to avoid it.”
Source: Sharḥ al-Muntahá al-Irādāt 3/497
عن البهوتي قال عمر الله رضي الله عنه اللَّهُمَّ أَرِنِي الْحَقَّ حَقًّا وَوَفِّقْنِي لِاتِّبَاعِهِ وَأَرِنِي الْبَاطِلَ بَاطِلًا وَوَفِّقْنِي لِاجْتِنَابِهِ
3/497 شرح منتهى الإرادات