Words have an object and meaning: Words usually have a corresponding object and meaning to go with that word. If you hear the word chair, then the concept of chair-ness arises in your mind. Some specific chair will probably come to mind. It may be a wooden chair or a metal chair, for example. It may be large, small, or this or that style, and it may be new or old. So, three things are there: 1) the word chair, 2) the concept of chair-ness, and 3) a specific chair.
The object that goes with OM is the universe: When the word OM is heard, what is the concept and object that comes to mind? What is that thing that goes along with that word, OM? The concept that goes with OM is the one-ness or entirety of the universe. The object that goes with the word OM is the entire universe, as a single unit, including the gross, subtle, causal planes of reality, both manifest and un-manifest. It means that whole, as if it was one, single object. It is that infinitely huge object, which is the object that goes with the word OM.
Awareness expands to contain the object: With attention turned inward, and reflecting on chair, the concept and image of chair arises. In the same way, do the same thing with the word OM, and allow your awareness to expand, as if it could contain the whole universe to go with that word.
Stretching the attention: There is a feeling of stretching, as if the attention had to get bigger and bigger, to contain the whole, the same way as the chair has a back, a seat, and legs, yet is collectively a chair. Continue to repeat OM, and continue to expand, so as to allow your attention to contain the whole of the object called OM.
