Why did ancient historians call Egypt "the gift of the Nile"?

The ancient historians called Egypt the "gift of the Nile", since the kingdom owed its survival to the annual flooding of the Nile and the resulting depositing of fertile silt. It was called the gift of the Nile because it had arable land which was good for farming.

They called it the gift of the Nile because the Nile was really important in the Egyptian times