Madonna claims her spiritual age is 36.
The 'Give It 2 Me' singer - who turns 50 tomorrow (16.08.08) - has been told by Kabbalah priests she is 14 years younger than her true birth age.
The star has since banned guests attending her celebrations from referring to her being 50, according to Britain's Daily Mirror newspaper.
She has also issued instructions informing her guests not to bring any cards, cakes or presents which state her true age.
Meanwhile, it has been revealed that Justin Timberlake - who teamed up with Madonna on the smash hit track '4 Minutes' earlier this year - was unsure what to buy the queen of pop for her special day, and so has settled for golfing vouchers.
Earlier this week, it was reported Madonna was considering delaying her birthday celebrations after twisting her ankle.
The singer was set to throw a lavish party at her country estate in Wiltshire, England, but suffered the injury while rehearsing for her upcoming world tour.
A source said: "Plans are very hush-hush but Madonna is definitely going to celebrate in style.
"Unfortunately, not everything has gone as expected as she's had many other things on her mind. On top of all the stress, she twisted her ankle over the weekend.
"She views this as a sign she should postpone the birthday bash and play it by ear instead."