Verse 11

11. Making the Self the lower fire stick and Aum the upper fire stick,  through repeated friction causing the heat of knowledge,  a wise man burns up his bonds.

"Making the Self (Truth),  the lower fire stick and Aum (desire,  Creation),  the upper fire stick"

Likening the Truth of the Self to one fire stick and the ignorance of material desire (Aum) to the other fire stick and the two being rubbed together to cause friction and heat,  this verse describes the sustained burning away of ignorance as a decision and commitment. 

"through repeated friction causing the heat of knowledge"

The wise Sage,  after having cognised the existence of the Absolute,  he will willingly experience again and again the heat caused by the friction of increasing knowledge and understanding (Truth of the Self),  as it rubes and chaffs against the up to now accepted bonds of ignorance and desire within Creation. 
Significantly each encountered experience of the heat of truth replacing ignorance strengthens the courageous and clarifies will.

"a wise man burns up his bonds"

The renouncing of the practices of untruth with its desire for gain and so forth is not without its natural fear.  In reaching for the Truth one has to stand alone in the face of judgements by others based on duality.  Gaining the faith to let go of ones delusions gives rise to the heat of battle in overcoming uncertainty.  The wise will have made a decision to disregard fear and doubt to gain the Truth.

One man cannot serve two masters.  One cannot deny or renounce the untruth of the Created while at the same time having ambitions within Creation. 
The bonds of desire are burnt away by the constant struggle towards the light of the Absolute Self or God.