Jami` at-Tirmidhi 2695
جامع الترمذي#2695Da'ifNarrated 'Amr bin Shu'aib:from his father, from his grandfather, that the Messenger of Allah (ﷺ) said: "He is not one of us who resembles other than us, no who resembles the Jews nor the Christians. For indeed greeting of the Jews is pointing the finger, and the greeting of the Christians is waving with the hand
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirHasan
Al-AlbaniHasan
Bashar Awad MaaroufDaif
Zubair Ali ZaiDaif
In-book reference: 42:8