What is the ruling on saying "Ay Wallah"? Is it considered an oath? May Allah reward you.

The phrase (Indeed, by Allah) is often used to emphasize speech without intending an oath, and it is considered a 'laghw' (idle talk) oath for which there is no expiation according to the majority of scholars, as conveyed by the Marwazi consensus and as an interpretation of Allah's saying: "Allah will not hold you accountable for the 'laghw' in your oaths." However, if the speaker intended an oath and firmly resolved it, then it becomes a binding oath that necessitates expiation.