A favorite passage:
Place me like a seal over your heart, like a seal on your arm;
for love is as strong as death, its jealousy unyielding as the grave.
It burns like blazing fire, like a mighty flame.
Many waters cannot quench love; rivers cannot sweep it away.
If one were to give all the wealth of one’s house for love,
it would be utterly scorned.
Song of Songs 8:6-7