Ah sure you know yourself
The all purpose Irish closer. Means everything, explains nothing, ends the conversation.
How's tings at home?" "Ah sure look, ya know yerself.

Shall I translate it into posh English for you, head?
Good day to you. Here it is in posh English.
"How are matters at home?" "Oh, one need hardly elaborate. You are as well acquainted with the human condition as I am."
Questions
What does ah sure you know yourself mean in Ireland?
The all purpose Irish closer. Means everything, explains nothing, ends the conversation.
How do you use ah sure you know yourself in a sentence?
“How's tings at home?" "Ah sure look, ya know yerself.”
Updated
On the list: Irish slang phrases