Tengri sits on the sky , mighty and powerful . His creations yer-sub earth — water is sacred for Turks in very early times.
Pouring water after the back of the outgoing guest can also be illustrated as an example of the “water cult” in Tengrism.
Idea is simple. Water is holy and most important thing for life. Throwing water behind traveling guests means.
Oh ” yer – earth“ let my people travel safe and fast. I offer you your most valuable thing Water.
Earth most valuable thing is water.
It travel’s and feeds underground spirits that could give them safe passage. It brings them luck. Also “su gibi git, su gibi gel “ go as water , come back as water. Fast as possible.
Mongols throwing milk or Siberian spilling milk is similar means…
Altay Dag on Quora