Al Kabir – The Great

Who is supremely great. The one and only being, whose existence is free of time, place and similarity to any of the creatures.
“Allah doth know what every female (womb) doth bear, by how much the wombs fall short (of their time or number) or do exceed. Every single thing is before His sight, in (due) proportion. He knoweth the Unseen and that which is open: HE IS THE GREAT, the most High. It is the same (to Him) whether any of you conceal his speech or declare it openly; whether he lie hid by night or walk forth freely by day.” (13:8.10) The Holy Quran
Allah’s essence is the perfection of greatness. He incomparably great.
His greatness is beyond measure. His nature is Greatness.

Al Kabir is the one possesses grandeur”. Ghazali

Quran tells us: "They shall say: What is it that your Lord said? They shall say: The truth. And He is the Most High, the Great". The Holy Quran (34:23)