SB 9.13.11

devā ūcuḥ
videha uṣyatāṁ kāmaṁ
 locaneṣu śarīriṇām
unmeṣaṇa-nimeṣābhyāṁ
 lakṣito ’dhyātma-saṁsthitaḥ
Word for word: 
devāḥ ūcuḥ — the demigods said; videhaḥ — without any material body; uṣyatām — you live; kāmam — as you like; locaneṣu — in the vision; śarīriṇām — of those who have material bodies; unmeṣaṇa-nimeṣābhyām — become manifest and unmanifest as you desire; lakṣitaḥ — being seen; adhyātma-saṁsthitaḥ — situated in a spiritual body.
Translation: 
The demigods said: Let Mahārāja Nimi live without a material body. Let him live in a spiritual body as a personal associate of the Supreme Personality of Godhead, and, according to his desire, let him be manifest or unmanifest to common materially embodied people.
Purport: 

The demigods wanted Mahārāja Nimi to come to life, but Mahārāja Nimi did not want to accept another material body. Under the circumstances, the demigods, having been requested by the saintly persons, gave him the benediction that he would be able to stay in his spiritual body. There are two kinds of spiritual bodies, as generally understood by common men. The term “spiritual body” is sometimes taken to refer to a ghostly body. An impious man who dies after sinful activities is sometimes condemned so that he cannot possess a gross material body of five material elements, but must live in a subtle body of mind, intelligence and ego. However, as explained in Bhagavad-gītā, devotees can give up the material body and attain a spiritual body free from all material tinges, gross and subtle (tyaktvā dehaṁ punar janma naiti mām eti so ’rjuna). Thus the demigods gave King Nimi the benediction that he would be able to stay in a purely spiritual body, free from all gross and subtle material contamination.

The Supreme Personality of Godhead can be seen or unseen according to His own transcendental desire; similarly, a devotee, being jīvan-mukta, can be seen or not, as he chooses. As stated in Bhagavad-gītā, nāhaṁ prakāśaḥ sarvasya yoga-māyā-samāvṛtaḥ: the Supreme Personality of Godhead, Kṛṣṇa, is not manifest to everyone and anyone. To the common man He is unseen. Ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ: Kṛṣṇa and His name, fame, qualities and paraphernalia cannot be materially understood. Unless one is advanced in spiritual life (sevonmukhe hi jihvādau), one cannot see Kṛṣṇa. Therefore the ability to see Kṛṣṇa depends on Kṛṣṇa’s mercy. The same privilege of being seen or unseen according to one’s own desire was given to Mahārāja Nimi. Thus he lived in his original, spiritual body as an associate of the Supreme Personality of Godhead.