Dua of tawakkul (trust in Allah)

قُلِ اللَّهُمَّ فَاطِرَ السَّمَاوَاتِ وَالْأَرْضِ عَالِمَ الْغَيْبِ وَالشَّهَادَةِ أَنتَ تَحْكُمُ بَيْنَ عِبَادِكَ فِي مَا كَانُوا فِيهِ يَخْتَلِفُونَ

Quli allahumma fatira assamawatiwal-ardi AAalima alghaybi washshahadatianta tahkumu bayna AAibadika fee ma kanoofeehi yakhtalifoon

Say (O Muhammad SAW): "O Allah! Creator of the heavens and the earth! All-Knower of the Ghaib (unseen) and the seen. You will judge between your slaves about that wherein they used to differ."

Source: Surah Az-Zumar - 39:46