Riyad as-Salihin, Book 6, Hadith 851 (In-Book) ⓘ

'Imran bin Husain (May Allah be pleased with them) reported: A man came to the Prophet and said: "As-Salamu 'Alaikum (may you be safe from evil). Messenger of Allah responded to his greeting and the man sat down. The Prophet said, "Ten (meaning the man had earned the merit of ten good acts)." Another one came and said: "As-Salamu 'Alaikum wa Rahmatullah (may you be safe from evil, and Mercy of Allah be upon you)." Messenger of Allah responded to his greeting and the man sat down. Messenger of Allah said, "Twenty." A third one came and said: "As-Salamu 'Alaikum wa Rahmatullahi wa Barakatuhu (may you be safe from evil, and the Mercy of Allah and His Blessings be upon you)." Messenger of Allah responded to his greeting and the man sat down. Messenger of Allah said, "Thirty."[Abu Dawud and At- Tirmidhi].

عن عمران بن الحصين رضي الله عنهما قال‏:‏ جاء رجل إلى النبي صلى الله عليه وسلم فقال‏:‏ السلام عليكم، فرد عليه ثم جلس، فقال النبي صلى الله عليه وسلم‏:‏ “عشر” ثم جاء آخر، فقال‏:‏ السلام عليكم ورحمة الله، فرد عليه فجلس، فقال‏:‏ ‏ "‏عشرون‏" ‏ ثم جاء آخر، فقال‏:‏ السلام عليكم ورحمة الله وبركاته، فرد عليه فجلس، فقال‏:‏ “ثلاثون” ‏(‏‏(‏رواه أبو داود والترمذي وقال‏:‏ حديث حسن‏)‏‏)‏‏.‏