198. Dua For Ruku Allahumma Laka Rakatu Bika Aman
اَللَّهُمَّ لَكَ رَكَعْتُ وَبِكَ آمَنْتُ وَلَكَ أَسْلَمْتُ خَشَعَ لَكَ سَمْعِيْ وَبَصَرِيْ وَمُخِّيْ وَعِظَامِيْ وَعَصَبِيْ
اَللّٰهُمَّ لَكَ رَكَعْتُ وَبِكَ اٰمَنْتُ وَلَكَ اَسْلَمْتُ خَشَعَ لَكَ سَمْعِىْ وَبَصَرِىْ وَمُخِّىْ وَعِظَامِىْ وَعَصَبِىْ
Allaahumma laka raka'tu, wa bika 'aamantu, wa laka 'aslamtu khasha'a laka sam'ee, wa basaree, wa mukhkhee, wa 'idhaamee, wa 'asabee
Translation
O Allah, to You I bow (in prayer) and in You I believe and to You I have submitted. Before You my hearing is humbled, as is my sight, my mind, my bones, my nerves.
Ali (RA) said, Rasulullah (ﷺ) used to say these words in rukoo.