The Persians didn't trust people who wouldn't drink, because this was a trait of liars. Admittedly, alcoholics drink because they lie too much; the drinking being the excuse they need to tell the truth, eventually they even become immune to the truth of spirits.https://twitter.com/tomxhart/status/1256541277501480961 …
This is however not exclusive to Persians any more. More secular cultures like Israeli and Lebanese cultures have similar sayings, perhaps through the early Persian influence / cultural exchange.