SB 7.10.11

śrī-bhagavān uvāca
naikāntino me mayi jātv ihāśiṣa
 āśāsate ’mutra ca ye bhavad-vidhāḥ
tathāpi manvantaram etad atra
 daityeśvarāṇām anubhuṅkṣva bhogān
Word for word: 
śrī-bhagavān uvāca — the Supreme Personality of Godhead said; na — not; ekāntinaḥ — unalloyed, without desires except for the one desire for devotional service; me — from Me; mayi — unto Me; jātu — any time; iha — within this material world; āśiṣaḥ — benedictions; āśāsate — intent desire; amutra — in the next life; ca — and; ye — all such devotees who; bhavat-vidhāḥ — like you; tathāpi — still; manvantaram — the duration of time until the end of the life of one Manu; etat — this; atra — within this material world; daitya-īśvarāṇām — of the opulences of materialistic persons; anubhuṅkṣva — you can enjoy; bhogān — all material opulences.
Translation: 
The Supreme Personality of Godhead said: My dear Prahlāda, a devotee like you never desires any kind of material opulences, either in this life or in the next. Nonetheless, I order you to enjoy the opulences of the demons in this material world, acting as their king until the end of the duration of time occupied by Manu.
Purport: 

One Manu lives for a duration of time calculated to be an aggregate of seventy-one yuga cycles, each of which equals 4,300,000 years. Although atheistic men like to enjoy material opulences and they endeavor with great energy to build big residences, roads, cities and factories, unfortunately they cannot live more than eighty, ninety or at the utmost one hundred years. Although the materialist exerts so much energy to create a kingdom of hallucinations, he is unable to enjoy it for more than a few years. However, because Prahlāda Mahārāja was a devotee, the Lord allowed him to enjoy material opulence as the king of the materialists. Prahlāda Mahārāja had taken birth in the family of Hiraṇyakaśipu, who was the topmost materialist, and since Prahlāda was the bona fide heir of his father, the Supreme Lord allowed him to enjoy the kingdom created by his father for so many years that no materialist could calculate them. A devotee does not have to desire material opulence, but if he is a pure devotee, there is ample opportunity for him to enjoy material happiness also, without personal endeavor. Therefore, everyone is advised to take to devotional service under all circumstances. If one desires material opulence, he can also become a pure devotee, and his desires will be fulfilled. It is stated in Śrīmad-Bhāgavatam (2.3.10):

akāmaḥ sarva-kāmo vā
 mokṣa-kāma udāra-dhīḥ
tīvreṇa bhakti-yogena
 yajeta puruṣaṁ param

“Whether one desires everything or nothing, or whether he desires to merge into the existence of the Lord, he is intelligent only if he worships Lord Kṛṣṇa, the Supreme Personality of Godhead, by rendering transcendental loving service.”