بسم الله والحمد لله
والصلاة والسلام على رسول الله ، وبعد
The Islaamic greeting of saying: “السلام عليكم ورحمة الله وبركاته”
is from the actions of the tongue (except when you are writing a message or
letter to someone). So, one cannot substitute it by merely raising or waving
the hand in the air, or nodding the head.
But if the person is at a distance and the voice is not
audible, then raising/waiving the hand along with saying “السلام عليكم ورحمة الله وبركاته”
will be right and In shaa Allaah will not be regarded as imitation.
Narrated `Amr bin Shu`aib from his father, from his
grandfather, that the Messenger of Allaah صلى الله عليه وسلم said: ❝He is not one of us who resembles other than us; do not
resemble the Jews or the Christians. For indeed greeting of the Jews is
pointing the fingers, and the greeting of the Christians is waving with the
hand.❞ [Sunan al-Tirmidhee (2695) and graded
as “Hasan li ghairihee” by Shaikh al-Albaanee in al-Saheehah (2194)]
Imaam al-Nasaa’ee reported that the Prophet صلى الله عليه وسلم said: ❝Do not greet with the greetings of the Jews or the
Christians, for their greetings is merely with (gesturing with their) hand,
(nodding with their) heads, and (pointing with their) fingers.❞
[Sunan al-Kubraa (10100) and the narrators in this chain are all reliable]