Matthew 23:7-8

23:7 and elaborate greetings in the marketplaces, and to have people call them ‘Rabbi.’ 23:8 But you are not to be called ‘Rabbi,’ for you have one Teacher and you are all brothers.

sn There is later Jewish material in the Talmud that spells out such greetings in detail. See H. Windisch, TDNT 1:498.