Ref # A Dictionary of Advanced Japanese Grammar p363
LR
nashi ni is usually used in written Japanese or in formal spoken Japanese
LR
when wa follows nashi ni, the final predicate has to be negative.
LR
before nashi ni can be either a noun or a "koto"-nominalized noun phrase
LR
I guess this would be the noun version of [Vn-zu] (not doing something)?
Antonio
what does o-motenashi have to do with the suffix (?) 'nashi'?
shijin
Nothing. #4122 おもてなし does not fit to this entry.
Miki
Agreed. omotenashi = hospitality. ex #4122 can be translated literally as: For your hospitality, I cannot completely express my gratefulness no matter how I thank you.
誠
Please tell me why in ex #4123 we use 済まされない? I think i should be 済ませない。Please help me!!