The handshake on tombstones is something I see continuously when strolling through a cemetery. It has been something haven't payed close attention to until I noticed something.
Is the handshake an earthly farewell to someone whom passed on or a welcoming gesture into the after life in Heaven. I'd like to see this as a symbol of matrimony on a married couples tombstone. Closely look at the cuffs of each hand next time. One being masculine and the other feminine as seen in this photograph.
Though nice thoughts of a married couple being back together, there are other speculations that the Devil himself has a say in this handshake. Clasping tight in a handshake dragging however it might have passed on into Hell. An unpleasant thought for sure and the true meaning us up for debate.
I do prefer the thought of two loved ones being together unto death do us part and reunited once again within Heaven's Gate forever until the end of all eternity!