The Great Rewards of Salaam.

A man came to the Prophet (ﷺ) and said: “As-Salamu ‘Alaikum (may you be safe from evil). 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 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 (ﷺ) responded to his greeting and the man sat down. Messenger of Allah (ﷺ) 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 (ﷺ) responded to his greeting and the man sat down. Messenger of Allah (ﷺ) said, “Thirty.”

[Abu Dawud and At- Tirmidhi].