April 2012) (Learn how and when to remove this template message) Wallah (Arabic: وَٱللّٰه‎, i.e. by God) is an Arabic expression meaning "I swear on Gods name" used to make a promise or express great credibility on an expresApril 2012) (Learn how and when to remove this template message) Wallah (Arabic: وَٱللّٰه‎, i.e. by God) is an Arabic expression meaning "I swear on Gods name" used to make a promise or express great credibility on an expression typically used as arabic slang.sion typically used as arabic slang.