The word: جُرُز (al-juruz) in verse 27: أَوَلَمْ يَرَوْا أَنَّا نَسُوقُ الْمَاءَ إِلَى الْأَرْضِ الْجُرُزِ فَنُخْرِجُ (Have they not seen that We drive water to the dry land, then We bring forth crops thereby - 27) means barren land where trees do not grow.
A wise system of irrigation
Usually the Qur'an mentions the irrigating of dry lands and the growing of crops therein by saying that the land receives rain, and becomes moist and growth-worthy. But, there is no mention of rain in this verse. Instead of that, it has been said that water itself is directed to move aground towards the dry land and thereby bring forth the growth of trees. In other words, the rain is made to fall on some other land and it is from there that water is directed to move in the form of carrier channels on the ground all the way to the dry land that receives no rain.
There is a hint embedded here. Some lands are so soft that they cannot withstand rains. If regular rains were made to fall there, buildings may collapse or trees may be uprooted. Therefore, nature has made its own arrangements for such lands. As for the rain itself, it is sent on a land which is capable of holding it. After that, water is made to flow from here all the way to such lands which cannot withstand rains - like the land of Egypt. And there are commentators who have pointed out to some lands of Yaman and Syria as being referred to in this verse. (as reported from Ibn ` Abbas and Al-Hasan)
And as for the correct position, this subject includes all such lands, with the inclusion of the land of Egypt known for scanty rains particularly. But, water from the rains in the Abyssinian territory of Africa comes into Egypt through the Nile bringing with it particles of the indigenous red soil which is good for the growth of crops. Therefore, the people of Egypt, despite that they have no rains in their country, do benefit by a supply of new water and soil every year. فَتَبَارَكَ اللَّـهُ أَحْسَنُ الْخَالِقِينَ (So, glorious is Allah, the Best of creators - 23:14).