I heard the Messenger of Allah ﷺ saying (the version of Sulayman has: The Messenger of Allah ﷺ used to say) after his prayer:- "O Allah, our Lord and Lord of everything, I bear witness that Thou art the Lord alone Who hast no partner; O Allah, Our Lord and Lord of everything, I bear witness that Muhammad is Thy servant and Thy apostle ; O Allah, our Lord and Lord of everything, I bear witness that all the servants are brethren; O Allah, our Lord and Lord of everything make me sincere to Thee, and my family too at every moment, in this world and in the world hereafter, O Possessor of glory and honour, listen to me and answer. Allah is incomparably great. O Allah, Light of the heavens and of the earth". The narrator Sulaiman b. Dawud said: "Lord of the heavens and of the earth, Allah is incomparably great. Allah is sufficient for me; and the excellent guardian is He; Allah is incomparably great. (Using translation from Abū Dāʾūd 1508)   

سَمِعْتُ رَسُولَ اللهِ ﷺ يَدْعُو فِي دُبُرِ الصَّلَاةِ يَقُولُ «اللهُمَّ رَبَّنَا وَرَبَّ كُلِّ شَيْءٍ أَنَا شَهِيدٌ أَنَّكَ الرَّبُّ وَحْدَكَ لَا شَرِيكَ لَكَ اللهُمَّ رَبَّنَا وَرَبَّ كُلِّ شَيْءٍ أَنَا شَهِيدُ أَنَّ مُحَمَّدًا عَبْدُكَ وَرَسُولُكَ اللهُمَّ رَبَّنَا وَرَبَّ كُلِّ شَيْءٍ أَنَا شَهِيدٌ أَنَّ الْعِبَادَ كُلَّهُمُ إخْوَةٌ اللهُمَّ رَبَّنَا وَرَبَّ كُلِّ شَيْءٍ اجْعَلْنِي مُخْلَصًا لَكَ وَأهْلِي فِي كُلِّ سَاعَةٍ فِي الدُّنْيَا وَالْآخِرَةِ ذَا الْجِلَالِ وَالْإِكْرَامِ اسْمَعْ وَاسْتَجِبْ اللهُ الْأَكْبَرُ الْأَكْبَرُ اللهُ نُورُ السَّمَوَاتِ وَالْأَرْضِ اللهُ الْأَكْبَرُ الْأَكْبَرُ حَسْبِيَ اللهُ وَنِعْمَ الْوَكِيلُ اللهُ الْأَكْبَرُ اللهُ الْأَكْبَرُ»