It is surprising when people argue that there is no mention in Gurbani about cutting or not cutting your bodily hair. In Japji Sahib, it is clearly stated to live our life in accordance to the Hukum (The Laws of Nature). This statement encompasses every trivial argument we make like justifying of Cutting/shaving/plucking of Hair from any part of the body.

Kesh or Bodily Hair grow as per the Hukum (The Laws of Nature) of the Almighty. Cutting edges of hair or plucking or shaving eyebrows/facial hair or shaving hair from any part of your body is a clear defiance of the Hukum (The Laws of Nature) of the Almighty.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sikh-sikhi-sikhism/32165-why-we-not-allowed-cut-hair.html

Now, about people who seek justification for cutting bodily hair, in cutting nails, i would request them to immediately stop cutting their nails and see what happens next? Doing your day to day chores, the nails will break-off automatically, even if you take utmost care to prevent them from breaking. This means Breaking-off of nails is perfectly in accordance of with the Hukum (The Laws of the Nature).

For me this fake argument of Nails v/s Hair ends right here! End of the Story!

The Hukum by the tenth Master to Keep Kesh is simply a reminder to follow this important Hukum ie. The Laws of Nature as ordained by the almighty.

But as Tejwant ji stated earlier in this discussion itself, a person who is hell bent upon to defy the word of the Guru or the Hukum, will eventually find a way to justify his/her acts.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=32165

Gurfateh!