The Prophet (ﷺ) recited Surat Al-Baqarah, Al 'Imran and An-Nisa' in one rak'ah, and he did not reach any verse that spoke of mercy but he asked Allah for it, nor any verse that spoke of punishment but he asked Allah for protection therefrom.
Sunan an-Nasa'i Book 11, Hadith 134
← Previous Hadith He prayed beside the Prophet (ﷺ) one night. He recited, and when he came to a verse that mentioned punishment, he would pause and seek refuge with Allah; if he came to a verse that mentioned mercy, he would pause for mercy. In his bowing he would say: 'Subhana Rabbil-Azim (Glory be to my Lord Almighty)' and in his prostration he would say: 'Subhan Rabbil-A'la (Glory be to my Lord the Most High).'"

Sunan an-Nasa'i Book 11, Hadith 133 Next Hadith → "I heard Abu Dharr say: 'The Prophet (ﷺ) stayed up all night repeating one verse. The verse was: 'If You punish them, they are Your slaves, and if You forgive them, verily, You, only You, are the All-Mighty, the All-Wise.'"

Sunan an-Nasa'i Book 11, Hadith 135