This is a tradition between both Christian and ancient Roman.
Some Quotations:
Love is composed of a single inhabiting two bodies -Aristotle
Being deeply loved by someone gives you strength, while loving someone deeply gives you courage. -Lao Tzu
Age does not protect you from love. But love, to some extent, protects you from age. -Anais Nin
The best and most beautiful things in the world cannot be seen or even touched. They must be felt with the heart. -Helen Keller
I have learned not to worry about love; but to honor its coming with all my heart.
-Alice Walker
I love you without knowing how, or when, or from where.I love you straightforwardly, without complexities or pride; so I love you because I know no other waythan this: where I does not exist nor you, so close that your hand on my chest is my hand, so close that your eyes close as I fall asleep.
-Pablo Neruda, "Love Sonnet XVII"
Leave the fingers open and it stays. Clutch it, and it darts away.