Narrated 'Abdur-Rahman bin 'Auf (RA):

The Prophet (ﷺ) prostrated and prolonged the Sajda, he then raised his head and said, "Jibrael (Gabriel) had come and given me glad tidings, thereafter I prostrated in gratitude to Allah." [Ahmad reported it and al-Hakim graded it Sahih (authentic)].

وَعَنْ عَبْدِ اَلرَّحْمَنِ بْنِ عَوْفٍ ‏- رضى الله عنه ‏- قَالَ : { سَجَدَ اَلنَّبِيُّ ‏- صلى الله عليه وسلم ‏-فَأَطَالَ اَلسُّجُودَ , ثُمَّ رَفَعَ رَأْسَهُ وَقَالَ :

إِنَّ جِبْرِيلَ آتَانِي , فَبَشَّرَنِي , فَسَجَدْت لِلَّهِ شُكْرًا

} رَوَاهُ أَحْمَدُ , وَصَحَّحَهُ اَلْحَاكِمُ .‏ [1]‏