The Prophet ﷺ said: If anyone invokes blessings on me once, Allah will bless him ten times. (Using translation from Abū Dāʾūd 1530)   

قَالَ رَسُولُ اللَّهِ ﷺ «مَنْ صَلَّى عَلَيَّ صَلَاةً وَاحِدَةً صَلَّى اللَّهُ عَلَيْهِ عَشْرًا»  

[Machine] The Prophet ﷺ came one day while people could see joy on his face. It was said to him, "O Messenger of Allah, we can see joy on your face that we have never seen before." He replied, "Yes, indeed. An angel came to me and said, 'O Muhammad, your Lord says, "Does it please you that no one from your Ummah prays upon you except that I pray upon them tenfold, and no one salutes you except that I salute them tenfold?"' I said, 'Yes, indeed.'"  

جَاءَ النَّبِيُّ ﷺ يَوْمًا وَهُوَ يُرَى الْبِشْرُ فِي وَجْهِهِ فَقِيلَ يَا رَسُولَ اللَّهِ إِنَّا نَرَى فِي وَجْهِكَ بِشْرًا لَمْ نَكُنْ نَرَاهُ؟ قَالَ أَجَلْ إِنَّ مَلَكًا أَتَانِي فَقَالَ لِي يَا مُحَمَّدُ إِنَّ رَبَّكَ يَقُولُ لَكَ أَمَا يُرْضِيكَ أَنْ لَا يُصَلِّيَ عَلَيْكَ أَحَدٌ مِنْ أُمَّتِكَ إِلَّا صَلَّيْتُ عَلَيْهِ عَشْرًا وَلَا يُسَلِّمَ عَلَيْكَ إِلَّا سَلَّمْتُ عَلَيْهِ عَشْرًا؟ قَالَ قُلْتُ بَلَى  

"The Messenger of Allah ﷺ said: 'Allah (SWT) has angels who travel around on Earth conveying to me the Salams of my Ummah.'" (Using translation from Nasāʾī 1282)  

قَالَ رَسُولُ اللَّهِ ﷺ «إِنَّ لِلَّهِ مَلَائِكَةً سَيَّاحِينَ فِي الْأَرْضِ يُبَلِّغُونِي عَنْ أُمَّتِي السَّلَامَ»