Waving when giving salaams
What is the ruling on giving Salaam by waving the hand?
It is not permissible to give Salaam by waving, the Sunnah is to speak when giving and when returning greetings of peace. Waving, on the other hand, is not allowed because it resembles the disbelievers, and it is contrary to what Allaah has legislated. In case that a person is far away and is not able to make the other person hear his greeting, then a Muslim can wave in a manner that indicates his greeting, there is no harm in that since there are reports to support it. Similarly, when one is praying, he can respond to a greeting by signalling with his hands, as is authentically reported in the Sunnah of the Prophet (sallallaahu alaihi wa sallam).
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah Vol. 8 Page 216