اللَّهُ اللَّهُ رَبِّي لا أُشْرِكُ بِهِ شَيْئًا

Allah Allah rabbi la ushriku bihi shay’an

Allah Allah is my Lord, I do not associate anything with Him

[abu Dawud, 2/87, Sahih ibn Majah 2/335]
Asma bint ‘Umayr (ra) said: “The Messenger of Allah (salAllahu alayhi wasalam) said to me: ‘Shall I not teach you some words which you can say at times of distress?
Another narration says that these words should be said 7 times.