How could a dam be built on the river Nile? That was the enigma. A humungous task, thought the great scientist Ibn ul Haytham to himself. For Imam Hakim (AS) had entrusted him with the arduous project of building a dam on the northern river that would prevent flooding, droughts and epidemics on the river banks. Ibn ul Haytham had been especially called over to Egypt for this project. A team of engineers had been summoned to accompany him to Aswan. Ibn ul Haytham's careful calculation and deep deliberation did not help. The more he worked, the more he was convinced that the task was impossible.

Ibn ul Haytham returned to Qahera, disappointed and downcast. How would he face the Imam (AS)? Would he be rebuked?

The Imam (AS) listened to Ibn ul Haytham as he listed the several complications. The Imam (AS) was sympathetic towards him.

In a short time following, the impossible was made possible, the dam was built, under detailed guidance and mapping from the Imam (SA).