The unimaginable God must be imaginable to Himself at least

132) Karturapi jnanabhagavat taduhyam svasya sattaayai .

(At least the author should know the unknown subject. Similarly, the unimaginable God must be imaginable to Himself at least so that the existence of any unknown item becomes valid).

At least one should know the unknown entity, if it has to exist. If it is unknown to every one, such entity does not exist at all. When you say that an unknown subject exists, it means that all most all do not know it except one or two persons. If no body knows the subject including the author, it means such subject does not exist at all. Therefore, the unimaginable God must be imaginable to Himself at least so that the existence of unimaginable God becomes valid.
Note:
Unimaginable characteristic is not a real characteristic. Because a real characteristic should remain unchanged even for self. Suppose you have got your form. Such and such form. That form is observed by others. The same form is also observed by you. But here if the unimaginable nature is the real characteristics of God, then He should be unimaginable to Himself also. The real characteristic will not change even if the observer is self. But God is imaginable to Himself. Your face is your characteristic the face is not changing when you observe it in the mirror. Your hand, it is observed by others and observed you also. It remains the same. If unimaginable nature is the real characteristic, God must be unimaginable to Himself also. But God is imaginable to Himself and there fore it is not the real characteristic. It is only an associated characteristic for the sake of others.