“The Eternal.” One of the ninety-nine names or attributes of God. It occurs once in the Qur’an, Surah cxii.; God the Eternal.”
In its original meaning, it implies a lord, because one repairs to him, in exigencies; or when applied, to God, because affairs are stayed or rested on Him. Hence, according to al-Mukham, in loco, and the Lisanu ‘l-‘Arab, it signifies the Being that continues for ever— the Eternal One.
Based on Hughes, Dictionary of Islam