the devil is in the [detail]

used in a situation where details need to be closely inspecterd or paid attention to

The idiom "the devil is in the detail" originated from the longer phrase "God is in the detail," which is often attributed to the German architect Ludwig Mies van der Rohe. Over time, the phrase evolved to its present form, suggesting that hidden difficulties or complications can arise from small or overlooked details. It is used to emphasize the importance of thoroughness and diligence in dealing with the finer aspects of a task or situation.

The contract seemed straightforward, but the devil is in the details, and we discovered unfavorable clauses that required careful negotiation.
When designing a building, architects know that the devil is in the details, as even the smallest oversight can compromise the entire structure.
The recipe called for precise measurements, and the devil is in the detail; a slight miscalculation could ruin the entire dish.
Planning an event requires meticulous organization because the devil is in the detail, and a missed logistical element can lead to chaos.
Writing a legal document demands attention to every word and clause because the devil is in the details, and a poorly worded phrase can have significant consequences.