روح والهوا بظهرك

Pronounced [ROOH WELHAWAA BE THAHRAK]

Very popular expression that is used to encourage someone to do something, it kind of show support to him/her

lit. mean "Go and may the wind be with you"

this term is most probably used in football (soccer) or with it in mind, when the wind helps one team to make better shots on the other team's goal.