Why does everyone cry when they part ways?

Weeping and laughter are two signs of emotion, and Allah is their cause. A person may weep at the separation of a beloved or dear one due to the pain and loneliness of separation. This is natural and there is no religious impediment to it, provided it is accompanied by patience with Allah’s decree and the absence of despair or discontent. Weeping does not negate patience, just as Jacob wept at the loss of Joseph, and just as the Prophet, peace and blessings be upon him, wept at the death of his son Ibrahim.