It beggars belief.

Meaning

It's so unbelievable or extraordinary that it's hard to comprehend.

Examples

• John: 'Alice won the lottery again!'<br>
• Alice: 'It beggars belief, doesn't it? This is my third win this year.'
• John: 'It beggars belief. Let's see the scientific evidence first.'
• Alice: 'They're claiming to have found a cure for cancer.<br>