When someone is going on a journey, or a long trip, we usually put water behind them. Like, we pour water on the ground after they leave, so that it makes them to come back.
My mom was born and raised in Tehran, Iran, and moved to the United States in 1976. One of the traditions she always kept was throwing water on the ground behind the car when someone leaves on a long trip. She prays and also makes each traveler kiss and walk under a Quran. She explained that because long trips are often dangerous and uncertain, she prays for our safekeeping. The water, she says is to make sure we come back. Shes not quite sure why, she thinks the water keeps a path on the ground on which we can return. Its a very widespread custom among Persians that is meant to help handle the stress of knowing loved ones could be in harms way, too far away to be helped in time.
I noticed that this folk belief, like many folk beliefs, is supported by a folk religious element. This makes practices that seem to invoke magic more acceptable among religious people. Water is given a mystical power as a path back home, but because that goes against religious teachings, in which magic is dismissed as a black art. In this case, the water is given this power by prayers to God that are not delineated in any sacred text. The Quran itself turns into a magical object, as well, in this case, but this is acceptable because it is assumed that the belief is in the word of God written inside that provides protection for the journey; however, it is used as if the book itself had its own separate powers.
Because travel is a liminal time, the leaving ceremony is highly ritualized. Kissing the binding of the Quran and walking under it while saying certain praises to God should be done right in order to ensure a safe trip. Forgetting to pour the water or perform some other part of this ritual could lead to trouble down the road.