It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that three men came to the Prophet (peace and blessings be upon him). The first said: "As-salamu alaykum (Peace be upon you)," and the Prophet (peace and blessings be upon him) replied to him: "Salamun alaykum wa rahmatullah (Peace be upon you and the mercy of Allah)." Then the second came and said: "As-salamu alaykum wa rahmatullah," and the Prophet (peace and blessings be upon him) replied to him: "Salamun alaykum wa rahmatullahi wa barakatuh (Peace be upon you, and the mercy of Allah and His blessings)." Then the third came and said: "As-salamu alaykum wa rahmatullahi wa barakatuh," and the Prophet (peace and blessings be upon him) replied: "Wa alaykum (And upon you)." The young man's father was sitting with the Prophet (peace and blessings be upon him), and he said: "O Messenger of Allah, you gave more to so-and-so and so-and-so in your reply, but you gave my son nothing more?" The Messenger of Allah (peace and blessings be upon him) said: "We found no room to add anything for him (because he himself had said all the words of the greeting), so we returned to him what he had said."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Ikrimah except Nafi' Abu Hurmuz; Abd al-Salam bin Mutahhar is alone in narrating it, and it is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) only with this chain."
Hadith Referenceالمعجم الأوسط / باب الميم / 5959
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 12007»