Islam taught Muslims to say Assalamu ‘alaykum (meaning ‘Peace be upon you’) and replaced all other forms of greeting.
In this small greeting is hidden an excellent and comprehensive prayer, kindness and affection for the young, and respect and attention for the elders.
Almighty Allah employs the same greeting in the Glorious Qur’an to address His beloved Prophets as a mark of His favour and esteem on them. ‘Peace be on Nuh among the people’ (37:79); ‘Peace be on Ibrahim’ (37:109) ‘Peace be on Musa and Harun’ (37:120); ‘Peace be on Ilyas’ (37:130); ‘Peace be on those sent (to warn)’ (37:59); and ‘Peace be on His slaves whom He has chosen’ (27:59). Believers will also be welcomed into Paradise with the same expression: ‘Enter here in peace, free of fear’ (15:46) and ‘Peace on you for the patience you observed. So, how excellent is the ultimate abode’ (13:24).
Salam is a distinctive practice of Islam and Muslims have been encouraged to spread this greeting. The Messenger of Allah sallallahu ‘alayhi wasallam said: “Oh people! Worship Allah, The Beneficent, feed His servants, and spread salam much, and you will reach Heaven in peace [and safety].” (al-Tirmidhi)
The importance of salam is further emphasized by the Prophet sallallahu ‘alayhi wasallam who advised that salam be exchanged a second time if after the meeting of two Muslims, even if it be for a brief moment, they are separated by a tree, wall, or rock, and meet again.
Salam is in essence a really beautiful teaching of Islam. It not only increases love and affection between Muslims but is also a cause of their forgiveness. The Prophet of Allah sallallahu ‘alayhi wasallam said, “When two Muslims meet and shake hands, and at the same time glorify Allah, and beg forgiveness for themselves, they shall be forgiven.” (Abu Dawud)