Riyad as-Salihin 850
'Imran bin Husain (May Allah be pleased with them) reported:
A man came to the Prophet (ﷺ) and said: "As-Salamu 'Alaikum (May peace be upon you). The Messenger of Allah (ﷺ) responded to his greeting and the man sat down. The Prophet (ﷺ) said, "Ten (meaning the man had earned the merit of ten good deeds)." Another one came and said: "As-Salamu 'Alaikum wa Rahmatullah (May peace be upon you and the Mercy of Allah)." The Messenger of Allah (ﷺ) responded to his greeting and the man sat down. The Messenger of Allah (ﷺ) said, "Twenty." A third one came and said: "As-Salamu 'Alaikum wa Rahmatullahi wa Barakatuhu (May peace be upon you and the Mercy of Allah and His Blessings)." The Messenger of Allah (ﷺ) responded to his greeting and the man sat down. The Messenger of Allah (ﷺ) said, "Thirty." [Abu Dawud and At- Tirmidhi, who classified it as Hasan] .
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)‏‏)‏‏.‏