WE RELATE FROM the book of at-Tirmidhī that ‘Amr ibn Shu‘ayb reported from his father, who reported from his grandfather, who narrated that the Prophet 
said: “He who imitates people other than us is not one of us. Do not imitate the Jews and the Christians [in their greeting]. The greeting of the Jews is to gesture with the fingers and the greeting of the Christians is to gesture with the shoulder [1]..” [2].At-Tirmidhī said that the isnād [of this hadith] is weak.
said: “He who imitates people other than us is not one of us. Do not imitate the Jews and the Christians [in their greeting]. The greeting of the Jews is to gesture with the fingers and the greeting of the Christians is to gesture with the shoulder [1]..” [2].At-Tirmidhī said that the isnād [of this hadith] is weak.Another hadith we relate from the book of at-Tirmidhī from Asmā’ bint Yazīd 
[states] that the Messenger of Allah passed through the mosque one day. A group of women was sitting there, and he gestured with his hand in greeting. [3].At-Tirmidhī regards this hadith as ḥasan.
[states] that the Messenger of Allah passed through the mosque one day. A group of women was sitting there, and he gestured with his hand in greeting. [3].At-Tirmidhī regards this hadith as ḥasan.This is interpreted as being that the Prophet combined speech with gesture, the proof of which is that Abū Dāwūd narrated this hadith and he said in his version that “he then greeted us with salām”.
combined speech with gesture, the proof of which is that Abū Dāwūd narrated this hadith and he said in his version that “he then greeted us with salām”.References
[1] Katif ‘a shoulder’. Other narrations have kaff, ‘the palm [of his hand]’, or akuff, ‘palms [of his hands]’.
[2] At-Tirmidhī (2696). Ibn Ḥajar grades it as ḥasan owing to its supporting narrations.
[3] At-Tirmidhī (2698), Abū Dāwūd (5204), and al-Bukhārī in al-Adab al-mufrad (1047).