Three is the Hungarian truth/justice!
3 is considered to be a magical number in ancient Hungarian legends, myths, religion and folk tales, e.g. the 3 princes, 3 princesses, 3 dragons, 3 tests, 3 wishes, 3 colors of the Hungarian flag, the 3 hills (hármashalom) in Hungarian heraldry.
Something is considered to be perfect, when it has been done 3 times. Some say the number 3 comes from the ancient idea of Trinity, the one that existed long before Jesus was born and says “3 is 1 and 1 is 3” (egy-háromság), the belief system that says everything is one.
We use this proverb when we are lucky/unlucky and something good/bad happens, then again something good/bad happens and we know that something good/bad will happen for the third time too and we say “három a magyar igazság”.