:salam:
Is it this one?
Ibn 'Umar (may Allah be pleased with them both) said, "The Messenger of Allah, may Allah bless him and grant him peace, did not omit saying the following words in the morning and evening:
'O Allah, I ask you for well-being in this world and the Next. O Allah, I ask you for forgiveness and well-being in my deen and in this world and in my family and my property. O Allah, veil my faults and calm my fears. O Allah, give me protection in front of me and behind me, on my right and my left and above me. I seek refuge by Your might from being overwhelmed from under me.'
Adab al Mufrad
English reference : Book 49, Hadith 1200
Arabic reference : Book 1, Hadith 1200
Arabic text of full hadeeth (inluding chain of narration). Text of dua is in green.
دَّثَنَا مُحَمَّدُ بْنُ سَلاَمٍ، قَالَ: حَدَّثَنَا وَكِيعٌ، عَنْ عُبَادَةَ بْنِ مُسْلِمٍ الْفَزَارِيِّ قَالَ: حَدَّثَنِي جُبَيْرُ بْنُ أَبِي سُلَيْمَانَ بْنِ جُبَيْرِ بْنِ مُطْعِمٍ قَالَ: سَمِعْتُ ابْنَ عُمَرَ يَقُولُ: لَمْ يَكُنْ رَسُولُ اللهِ صلى الله عليه وسلم يَدَعُ هَؤُلاَءِ الْكَلِمَاتِ إِذَا أَصْبَحَ وَإِذَا أَمْسَى:
اللَّهُمَّ إِنِّي أَسْأَلُكَ العَفْوَ وَ الْعَافِيَةَ فِي الدُّنْيَا وَالْآخِرَةِ. اللَّهُمَّ إِنِّي أَسْأَلُكَ الْعَفْوَ وَالْعَافِيَةَ فِي دِينِي وَدُنْيَايَ، وَأَهْلِي وَمَالِي. اللَّهُمَّ اسْتُرْ عَوْرَاتِي، وَآمِنْ رَوْعَاتِي. اللَّهُمَّ احْفَظْنِي مِنْ بَيْنِ يَدَيَّ وَمِنْ خَلْفِي، وَعَنْ يَمِينِي وَعَنْ شِمَالِي، وَمِنْ فَوْقِي، وَأَعُوذُ بِعَظَمَتِكَ مِنْ أَنْ أُغْتَالَ مِنْ تَحْتِي.
Link:
http://www.sunnah.com/urn/2311970