يَا مُقَلِّبَ الْقُلُوبِ ثَبِّتْ قَلْبِي عَلَى دِينِكَ
Anas ibn Maalik (may Allah be pleased with him) said, that the messenger of Allah (may the peace and blessings of Allah be upon him) used to profusely say:
"O turner of hearts, keep my heart firm upon Your religion."
"O turner of hearts, keep my heart firm upon Your religion."
Sources:
At-Tirmidhee No# 2140, 3522