The Prophet ﷺ said: “The most beloved of your names to Allah are ʿAbd Allah and ʿAbd al-Rahman” (Muslim 2132), and scholars add to them all names formed on a name of Allah. The name al-Hafiz occurs 3 times in the Quran; its page in the 99 Names section gives its meaning and verses.
ʿAbd al-Hafiz joins ʿabd with al-Hafiz, from the root h-f-z of guarding and preserving: the One who guards and preserves all things and keeps account of everything. The same root gives hafiz, one who knows the Quran by heart. The name is common in Algeria and Morocco as Abdelhafid.
But if you turn away, then I have already conveyed that with which I was sent to you. My Lord will give succession to a people other than you, and you will not harm Him at all. Indeed my Lord is, over all things, Guardian."
And he had over them no authority except [it was decreed] that We might make evident who believes in the Hereafter from who is thereof in doubt. And your Lord, over all things, is Guardian.