1.”As-Salaamu Alaikum” is a means of immense reward
A man passed by the Messenger of Allaah (Sal Allaahu Alaihi wa Sallam) while he was sitting with others, and said “As-salaamu ‘alaykum.”
The Prophet (Sal Allaahu Alaihi wa Sallam) said, “[He will have] ten hasanaat.”
Another man passed by and said “As-Salaamu Alaikum wa Rahmatullaah (peace be upon you and the mercy of Allaah).”
The Prophet (Sal Allaahu Alaihi wa Sallam) said, “[He will have] twenty hasanaat.”
Another man passed by and said “As-Salaamu Alaikum wa Rahmatullaahi wa Barakaatuh (peace be upon you and the mercy of Allaah and His blessings).”
The Prophet (Sal Allaahu Alaihi wa Sallam) said, “[He will have] thirty hasanaat.”
2.”As-Salaamu Alaikum” is an aspect of Imaan
Once a man asked the Prophet (Sal Allaahu Alaihi wa Sallam) about which aspect of Islam was best. The Prophet (Sal Allaahu Alaihi wa Sallam) replied: “Feeding the hungry, and saying salaam to those you know and those you don’t know.” (Bukhaari and Muslim)
3. “As-Salaamu Alaikum” is a means of entering Jannah
The Prophet (Sal Allaahu Alaihi wa Sallam) said: “You will not enter Paradise until you believe, and you will not believe until you love one another. Shall I not tell you about something which, if you do it, you will love one another? Spread salaam (the greeting of peace) among you.” (Muslim)
4. “As-Salaamu Alaikum” gets rid of sins
The Prophet (Sal Allaahu Alaihi wa Sallam) also said, “When two Muslims meet (give salaam), and shake hands, they are forgiven their sins before they part (with each other).” (Abu Dawud)
5. “As-Salaamu Alaikum” is the greeting of the people of Jannah
“Then, those that feared their Lord shall be driven in companies into Paradise. When they draw near its gates will be opened, and its keepers will say to them: “Salaamun ‘Alaikum” (Peace be upon you), you have done well. Enter and live in it forever.” (Surah Zumar:73)