"Jerusalem stone is the only stone that hurts
It has a network of nerves" 
Yehuda Amichai

Seventy names to Jerusalem. Seventy peoples on the earth. Seventy bulls sacrificed for their welfare in the seven days of the holyday of Succoth. Seventy is the letter ‘Ain in Hebrew. And ‘Ain means eye. Seventy eyes to Jerusalem, seventy faces, seventy ways to look at her. Seventy names of God, seventy faces to each knowledge.  
‘Ain / Seventy is also a source of water, a spring, as there are many around Jerusalem. And as water can turn into wine, seventy is also the numerical vaue of the word “yain / wine”, and “Jerusalem has seventy names according to the value of “wine” that is the secret of knowledge and that his number is seventy”, writes the Ben Ish Hai. As the seventy / wine opens up buried secrets in us, so the seventy / eye opens up the secrets of reality.  
And ‘ain is the first letter of the word ‘or / skin. But the qabbalist HaShela tells us that at the end of time the ‘ain / seventy will be repaired and will become an alef / one. We will see under the skin and ‘or / skin will become or / light. Seventy nations of the earth but under our skin the same light. Seventy times my eyes try to catch their reflections in the city of the seventy names. Seventy portraits of my being mirrored in the other. Seventy photographs.