> Can you show the rule from the books of grammars of Vedic Sanskrit or from Classical Sanskrit > that allows you to write a genitive singular for example the word in context "Sunasya Shepa" as
> per your take, with a Visarga "Suna : Shepa" or even "SunasShepa".
But Francesco is not assuming that the word for 'dog' being used is _śuna_, whose genitive singular (g.s.) is _śunasya_; he is assuming that word being used is the form _śvan_, whose g.s. is _śunas_ (or _śunaḥ_if you prefer).
> Put the rule in response and then explain that with help of use of Shunah Shepa in a Vedic
> mantra, avoid making unfounded justification.
You may find the analysis at http://www.vedakosh.com/rig-veda/mandal-5/sukta-002/mantra-rig-05-002-007 helpful. The phrase you highlighted earlier, _śunaścicchepaṁ_, is analysed as _śunaḥ-śepam cit_.
One odd thing I've seen is the writing of the phrase in *Devanagari* with word breaks as _śunaś cic chepaṁ_. Is this normal? I've also seen it with no spaces, but halants at the word boundaries, and I find it hard to believe the font lacked the ligatures or half-forms.
Richard.