In the texts of Russian epics and fairy tales, expressions are often found with the words GOY ESI, for example: “Oh you goy you, good fellow! What kind of speech turnover was this earlier used by our ancestors?
It turns out goy is an ancient Russian word that has meanings associated with life and life-giving power. It makes sense to "live", "hello". By the way, the word "goy" is a cognate of the well-known "gove" - to abstain, to cleanse and restrict in food. The root goy is also associated with the word "outcast", which is preserved in modern language, meaning outdated.
And the word "is" is nothing more than the obsolete "is", which is used as a linking word in a sentence.
As a result, it turns out that Goi esi is a greeting-magnifying formula meaning "be alive!" or "be healthy!", which was used by our ancestors during the greeting, expressing respect for a person. It is clear that now no one is expressed like that. It was replaced by "hello" or the familiar "great", but still sometimes the expression "goy thou" can still be heard when reading a Russian folk tale or legend.