اَللّٰهُمَّ إِنِّي أَسْأَلُكَ الثَّبَاتَ فِي الأَمْرِ وَأَسْأَلُكَ عَزِيمَةَ الرُّشْدِ وَأَسْأَلُكَ شُكْرَ نِعْمَتِكَ وَحُسْنَ عِبَادَتِكَ وَأَسْأَلُكَ لِسَانًا صَادِقًا وَقَلْبًا سَلِيمًا وَأَعُوذُ بِكَ مِنْ شَرِّ مَا تَعْلَمُ وَأَسْأَلُكَ مِنْ خَيْرِ مَا تَعْلَمُ وَأَسْتَغْفِرُكَ مِمَّا تَعْلَمُ إِنَّكَ أَنْتَ عَلاَّمُ الْغُيُوبِ
Allaahumma innii as’alukath-thabaata fil-‘amr(i), wa as’aluka ‘aziimatar-rushd(i), wa as’aluka shukra ni’matik(a), wa husna ibaadatik(a), wa as’aluka lisaanan saadiqa(n), wa qalban saliima(n), wa khuluqam mustaqiima(n), wa a’uudhu bika min sharri maa ta’lam(u), wa as’aluka min khayri maa ta’lam(u), wa astaghfiruka mimmaa ta’lam(u), innaka anta ‘Allaamul-ghuyuub. (Shaddaad ibn ‘Aws. Sunan at-Tirmidhii #3329; Ibid. Mustadrak Haakim #72/1872)
O Allah, I beg You for steadfastness in religious affairs. I beg You for determination to follow the guidance. I beg You to enable me to show gratitude for Your bounties and to worship You with the best devotion. I beg You for a truthful tongue, a sound heart, and an upright character. I seek Your protection from the evil of all that only You are aware of. I beg You for the good that only You know. And I seek forgiveness from You for what You know (of my sins). Surely, You are the All-Knowing of the hidden.
Ameen
sound heart: one that is protected from corrupted beliefs and evil desires (Tuhfah al-Ahwadhii).
The Prophet Muhammad (sallallahu alayhi wa sallem) used to say this du’aa in the last sitting of the fourth rak’ah before the ending salaam. It is reported that after teaching this du’aa to Sayyidnaa Shaddaad ibn Aws (ra), Prophet Muhammad (sallallahu alayhi wa sallem) said: “When you see people collecting gold and silver as treasures, consider this du’aa as your treasure.”
(Source: Khalid Baig’s commentary to du’aa #58 in the Accepted Whispers: Munajat-e-Maqbul)