A jewish mother ,a mindreader

Ruth looks down over her balcony and sees her son Mervyn playing football on the lawn.
"Mervyn," she shouts down at him, "Mervyn, please come inside at once."
Mervyn looks up at her and says, "Why mummy? Am I cold again?"
"No Mervyn, you're not cold," replies Ruth, "you want to eat."