"The Prophet (ﷺ) was met by some affair that made him happy, so he prostrated to Allah." [Abu 'Eisa said:] This Hadith is Hasan Gharib, we do not know of it except from this route, as a narration of Bakkar bin 'Abdul-'Aziz. This is acted upon according to most of the people of knowledge, they held the view that one could perform the prostration of gratitude. And Bakkar bin 'Adbul-'Aziz bin Abi Bakrah is Muqarib (average) in Hadith.
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا أَبُو عَاصِمٍ، حَدَّثَنَا بَكَّارُ بْنُ عَبْدِ الْعَزِيزِ بْنِ أَبِي بَكْرَةَ، عَنْ أَبِيهِ، عَنْ أَبِي بَكْرَةَ، أَنَّ النَّبِيَّ صلى الله عليه وسلم أَتَاهُ أَمْرٌ فَسُرَّ بِهِ فَخَرَّ لِلَّهِ سَاجِدًا . قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ لاَ نَعْرِفُهُ إِلاَّ مِنْ هَذَا الْوَجْهِ مِنْ حَدِيثِ بَكَّارِ بْنِ عَبْدِ الْعَزِيزِ . وَالْعَمَلُ عَلَى هَذَا عِنْدَ أَكْثَرِ أَهْلِ الْعِلْمِ رَأَوْا سَجْدَةَ الشُّكْرِ . وَبَكَّارُ بْنُ عَبْدِ الْعَزِيزِ بْنِ أَبِي بَكْرَةَ مُقَارِبُ الْحَدِيثِ .
Tirmizi
The Book on Military Expeditions • Hadith 1621