The Evangelical Universalist Forum

deuteronomy 6:4 the trinity ?

some people say that God in this verse is said to be an UNITY WITH MORE THAN ONE THING IN HIM
i am convinced by that
my question is :it is obvious that the son and his father are God, but is there a proof in the old testament that there is a third person in God ? (i read that there was an evidence, but i don’t find again the article about that on the internet)
thank you very much

i have found the answer