The phrase "as sure as the sun will rise tomorrow" is a simile that expresses absolute certainty. It compares something to the daily, predictable rising of the sun, implying that the thing being compared is just as certain to happen.

Here's why it's so powerful:

* Universality: Everyone experiences the sunrise, making it a universally understood and accepted phenomenon.

* Reliability: The sun rises every day, making it a reliable and dependable event.

* Unquestionable: The rising of the sun is beyond doubt or debate.

Therefore, saying something is "as sure as the sun will rise tomorrow" means it is completely certain, absolutely guaranteed, or beyond any reasonable doubt.

Examples:

* "I will be there tomorrow, as sure as the sun will rise."

* "She'll win the race, as sure as the sun will rise tomorrow."

* "You can count on him to be there, as sure as the sun will rise."