Verse 14

14. Again,  through his connection with deeds done in previous births,  that very jiva returns to the dream-state,  or the waking state.  The being who sports in the three cities,  the states of wakefulness,  dream and deep sleep,  from Him has sprung up all diversity.  He is the substratum,  the bliss,  the indivisible Consciousness,  in whom the three cities dissolve themselves.

"Again,  through his connection with deeds done in previous births that very jiva returns to the dream-state,  or the waking state".

This statement refers to the experience of rebirth within the consciousness that failed to realise the Non-Dual Absolute before the death of the form.
The meaning is that due to consciousness still being deluded through desire and duality it was lead back to the means of achieving those material desires,  that means within the consciousness of material creation.

"The being who sports in the three cities,  the states of wakefulness,  dream and deep sleep,  from Him has sprung up all diversity"

This statement is Confirmation that the being who desires is the being who is reborn into the three cities of Creation ("wakefulness,  dream and deep sleep").
The meaning is that the desires that cause rebirth are the very desires that cause the Creation of the material realm ("all diversity") in order to accommodate the desirous being.

"He is the substratum,  the bliss",

This verse confirms the Absolute Self as the substratum for this dualistic creation of the ignorant.  Upon realisation of the reality of the Self this realised consciousness attains the Truth and bliss of Absolute Consciousness.

"the indivisible Consciousness",

All the descriptions of "states of being" that are used such as waking state or dream state or birth experience and so forth are merely for the convenience of explanation.  In truth all of Existence is the One indivisible Non-Dual Consciousness alone. All divisions or states are Maya causing that experience in the one existence of Consciousness.

"in whom the three cities dissolve themselves".

Within this false (Maya) creation of duality the "three cities" (the states of wakefulness,  dream and deep sleep) are subsumed once more as indivisible Consciousness of Absolute Knowledge Alone.

The reference to "previous births" means a recurring life experience.  This repeated experience of birth is due to his "connection with deeds done in previous births",  which means each life experience,  or life state,  has been "lived" without relinquishing desire.  Desires exist only within material Creation therefore desires can only be satisfied by material creation.  The meaning here is that when this "jiva" consciousness experiences the death of the form it retains the consciousness of desire therefore it returns to,  or retains the state of experiencing birth life and death,  meaning it returns to the "waking state",  which is still a kind of dreaming,  taking up another form. 
From this very "jiva" consciousness of desire the appearance of duality and the universe arise,  "sprung up all diversity",  which is maintained so long as this Solitary jiva maintains desire. 
"Him" This Solitary "jiva" is One indivisible solitary Consciousness of existence experiencing the Maya of desire and the "three cities" of "wakefulness,  dream and deep sleep".  When this "jiva" wakes up from desire and emerges into Absolute Consciousness the three states will "dissolve themselves" to unmanifest knowledge which is that indivisible Absolute Consciousness,  just as a dream dissolves itself into the waking consciousness of the man arising in the morning.