The Prophet Said About Etiquette of Greeting

يُسَلِّمُ الصَّغِيرُ عَلَى الْكَبِيرِ، وَالْمَارُّ عَلَى الْقَاعِدِ، وَالْقَلِيلُ عَلَى الْكَثِيرِ

“The youngest should greet the older and the walking person should greet the sitting one, and the small number of persons should greet the large number of persons.”