Al-Furqan 25:16

Lahum feeha ma yashaoonakhalideena kana AAala rabbika waAAdanmas-oola

For them therein is whatever they wish, [while] abiding eternally. It is ever upon your Lord a promise [worthy to be] requested.

For them there will be whatever they wish, while they will be eternal. This is a promise undertaken by your Lord, (the fulfillment of) which is worth praying for.