Silsilah as-Sahihah 2639 — Etiquette of Salam

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: "The rider should greet those who are walking, the one who is walking should greet the one who is sitting, and those who are fewer in number should greet those who are greater in number."