He heard the Prophet ﷺ, when he raised his head in the last rak'ah of the subh prayer, say: "O Allah, curse so-and-so and so-and-so," supplicating against some of the hypocrites. Then Allah revealed the words: "Not for you is the decision; whether He turns in mercy to (pardon) them or punishes them; verily, they are the wrongdoers." (Using translation from Nasāʾī 1078)
أَنَّهُ سَمِعَ رَسُولَ اللهِ ﷺ قَالَ فِي صَلَاةِ الْفَجْرِ حِينَ رَفَعَ رَأْسَهُ مِنَ الرَّكْعَةِ قَالَ رَبَّنَا وَلَكَ الْحَمْدُ فِي الرَّكْعَةِ الْآخِرَةِ ثُمَّ قَالَ اللهُمَّ الْعَنْ فُلَانًا وَفُلَانًا دَعَا عَلَى نَاسٍ مِنَ الْمُنَافِقِينَ فَأَنْزَلَ اللهُ تَعَالَى {لَيْسَ لَكَ مِنَ الْأَمْرِ شَيْءٌ أَوْ يَتُوبَ عَلَيْهِمْ أَوْ يُعَذِّبَهُمْ فَإِنَّهُمْ ظَالِمُونَ} [آل عمران 128]