The word kufu' as used in the original means an example, a similar thing, the one equal in rank and position. In the matter of marriage, kufu' means that the boy and the girl should match each other socially.
The verse means that there is no one in the entire universe, nor ever was, nor ever can be, who is similar to Allah, or equal in rank with Him, or resembling Him in His attributes, works and powers in any degree whatever.
(6:59) He has the keys to the realm that lies beyond the reach of human perception; none knows them but He. And He knows what is on the land and in the sea; there is not a leaf which falls that He does not know about and there is not a grain in the darkness of the earth or anything green or dry which has not been recorded in a Clear Book.