This is simply to say (with staggering implications) that God exists because he exists (Exod 3:13–14). He is not dependent upon anything or anyone for his thoughts (Rom 11:33–34), his will (Rom 9:19; Eph 1:5), his power (Ps 115:3), or his counsel (Ps 33:10–11).

In a nutshell, we exist because our parents existed (past tense), but God exists because he exists (eternal tense).

This attribute does not imply that he created himself somewhat similarly (in a much different arena) to a self-made millionaire! To the contrary, his self-existence is not based on his power, but upon his eternality.