Al-Tirmidhi Hadith 888         Narrated by Anas ibn Malik

A man asked the Prophet (saws): ‘O Messenger of Allah (saws)! When any one of us meets a Muslim brother or a friend, should he then bow his head (as a sign of courtesy to him)?’  He (saws) said: ‘No.’ The man said: ‘Should he embrace and kiss him?’  He (saws) said: ‘No.’ The man then asked: ‘Should he clasp his hands?’  He (saws) said: ‘Yes.’

Al-Tirmidhi Hadith 4679        Narrated by Al-Bara' ibn Azib

The Prophet (saws) said: "Two Muslims will not meet and shake hands without having their sins forgiven them before they separate.

Sahih Al-Bukhari Hadith 8.279         Narrated by Qatada

I asked Anas bin Maalik (who served the Prophet (saws) in his (saws) house for ten years), "Was it a custom of the companions of the Prophet (saws) to shake hands with one another?"  He said, "Yes."

Al-Tirmidhi Hadith 4681        Narrated by Abu Umamah

Allah's Messenger (saws) said, "The perfect way for one of you to visit an invalid is for you to put your hand on his forehead or on his hand and ask him how he is; and the perfect way for you to greet one another is to shake hand