When there was nothing, Allah T'ala was, and when there will be nothing, He will be. He is the most Manifest of all the manifest, for whatever manifests itself in the world, does only by His attributes and His works and His light. And He is the Most Hidden of all the hidden, for not only do the senses fail to percieve Him but the intellect and thought and imagination also cannot attain to His essence and reality.
The best commentary in this regard are the words of a supplication of the Holy Prophet (upon whom be Allah's peace and blessings). which Imam Ahmad, Muslim, Tirmidhi, and Baihaqi have related on the authority of Hadrat Abu Hurairah, and Hafiz Abu Ya'la Mosuli in his Musnad on the authority of Hadrat 'A'ishah:
"Antal Awwal, fa-laisa qablaka shai'in; wa Antal Akhir fa-laisa ba 'daka shai 'in; wa Antal Zahir, fa-laisa fauqaka shai in; wa Antal Batin, fa laisa dunaka shai'in. " "You alone are the First; none is before You; You alone are the Last: none is after You; You alone are the Exalted none is above You; You alone are the Hidden: none is more hidden than You. "
Here, the question arises: How does this accord with the immortality and eternal life of the dwellers of Paradise and Hell mentioned in the Qur'an when Allah alone is the Last and Eternal? Its answer has been provided by the Qur'an itself: "Everything is perishable except Allah Himself." (AI-Qasas: 88). In other words no creature is immortal in its personal capacity; if a thing exists or continues to exist, it does so because Allah keeps it so, and can exist only by His letting it exist; otherwise in its own capacity everything is perishable except Allah. Immortality in Heaven and Hell will not be bestowed upon somebody because he is immortal by himself, but because AIIah will grant him eternal life. The same is true of the angels: they are not immortal by themselves. When Allah willed they came into existence, and will continue to exist only as long as He wills.