Hadith on Greetings: The best greeting is peace, mercy, and blessings from Allah be upon you

Imran ibn Hussein reported: A man came to the Prophet, peace and blessings be upon him, and he said, “Peace be upon you.” The Prophet said, “Ten good deeds.” Then another man came to the Prophet and he said, “Peace be upon you and the mercy of Allah.” The Prophet said, “Twenty good deeds.” Then another man came to the Prophet and he said, “Peace be upon you and the mercy of Allah and His blessings.” The Prophet said, “Thirty good deeds.”

Source: Sunan At-Tirmidhi 2689

Grade: Sahih (authentic) according to At-Tirmidhi

عَنْ عِمْرَانَ بْنِ حُصَيْنٍ أَنَّ رَجُلًا جَاءَ إِلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَقَالَ السَّلَامُ عَلَيْكُمْ قَالَ قَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَشْرٌ ثُمَّ جَاءَ آخَرُ فَقَالَ السَّلَامُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عِشْرُونَ ثُمَّ جَاءَ آخَرُ فَقَالَ السَّلَامُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ فَقَالَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ثَلَاثُونَ

2689 سنن الترمذي  كِتَاب الِاسْتِئْذَانِ وَالْآدَابِ  بَاب مَا ذُكِرَ فِي فَضْلِ السَّلَامِ

قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ غَرِيبٌ