Shaking hands: our Prophet (PBUH) said: " whenever two Muslims meet shaking the hands of each other, Allah would forgive them before their departure " (Narrated by Abu Dawood, Al Tirmithi and Ibn Majah) An Nawawi said: you should know that it is preferred to shake hands in every time they meet. So dears, try to shake hands with whoever you salute with a smiley face; thus you will be applying three sunnahs at once.