اَللَّهُ اَللَّهُ رَبِّي لَا أُشْرِكُ بِهِ شَيْئًا

Allahu Allahu Rabbee laa 'ushriku bihi shay'an.

Allah, Allah is my Lord. I do not associate anything with Him. Narrated Asma' daughter of Umays (RA): The Messenger of Allah (ﷺ) said to me: May I not teach you phrases which you utter in distress? These are: (The dua is mentioned avobe)

Reference: Abu Dawud : 1525