Increasing on the Established Islamic Greeting
Question :
Is it permitted in Islam to say more than the established greeting, "As-Salamu Alaykum wa-Rahmatullahi wa-Bar- akatuhu"?
Answer:
One should not initiate the greeting with more than "As- Salamu Alaykum wa-Rahmatullahi wa-Barakatuhu", due to the absence of anything confirmed to support that, according to what we know. May Allah send peace and blessings upon Muhammad, his family, and his Companions.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 8 Page 216