How to Greet Another Muslim (Assalamu'alaikum Warahmatullahi Wabarakatuh)

حَدَّثَنَا مُحَمَّدُ بْنُ كَثِيرٍ، أَخْبَرَنَا جَعْفَرُ بْنُ سُلَيْمَانَ، عَنْ عَوْفٍ، عَنْ أَبِي رَجَاءٍ، عَنْ عِمْرَانَ بْنِ حُصَيْنٍ، قَالَ جَاءَ رَجُلٌ إِلَى النَّبِيِّ صلى الله عليه وسلم فَقَالَ السَّلاَمُ عَلَيْكُمْ ‏.‏ فَرَدَّ عَلَيْهِ السَّلاَمَ ثُمَّ جَلَسَ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ عَشْرٌ ‏"‏ ‏.‏ ثُمَّ جَاءَ آخَرُ فَقَالَ السَّلاَمُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ ‏.‏ فَرَدَّ عَلَيْهِ فَجَلَسَ فَقَالَ ‏"‏ عِشْرُونَ ‏"‏ ‏.‏ ثُمَّ جَاءَ آخَرُ فَقَالَ السَّلاَمُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ ‏.‏ فَرَدَّ عَلَيْهِ فَجَلَسَ فَقَالَ ‏"‏ ثَلاَثُونَ ‏"‏ ‏.‏

Narrated Imran ibn Husayn: A man came to the Prophet (ﷺ) and said: Peace be upon you! He responded to his salutation. He then sat down. The Prophet (ﷺ) said: Ten. Another man came and said: Peace and Allah's mercy be upon you! He responded to his salutation when he sat down. He said: Twenty. Another man came and said: Peace and Allah's mercy and blessings be upon you! He responded to him and said when he sat down: and blessings be upon you! He responded to him and said when he sat down: Thirty. [Sahih (Albani). Abu Dawud: 5195]