Surah 2. Al-Baqara, Ayah 126

The root salama in the word Islam implies (among other ideas) the idea of Peace, and therefore when Mecca is the city of Islam, it is also the City of Peace. The same root occurs in the latter part of the name Jerusalem, the Jewish City of Peace. When the day of Jerusalem passed (see verse 134 or 141 below), Mecca became the "New Jerusalem" - or rather the old and original "City of Peace" restored and made universal.

The territory of Mecca is barren and rocky, compared with, say Taif, a city 70-75 miles east of Mecca. A prayer for the prosperity of Mecca therefore includes a prayer for the good things of material life. This is the literal meaning. But note that the opposition in this verse is between the fruits of the Garden for the righteous and the torments of the Fire for the evil ones - a spiritual allegory of great force and aptness.