Say, “My Rabb, forgive and bestow Your grace! You are the best of those who are Rahim!”
Sayyed Abbas Sadr-Ameli
And (O Muhammad) say: 'My Lord! Forgive and have mercy, (for) You are the best of the merciful ones'
Al-muntakhab fi tafsir al-Qur'an al-Karim
And so, pray to Allah invoking Him for mercy, expressing your thoughts in words, thus: "O Allah, my Creator, You ascribed mercy and forgiveness, forbearance and indulgence unto Yourself. Forgive me and have mercy on me and on those whom You will; You are indeed the Most Merciful Whose mercy is extended to the wide circle of the all."
And he who prays to another (presumed) god along with Allah, having no proof with him of it (being a god), then (the responsibility of taking) his account (rests) only on Allah. The infidels will certainly not be successful.