Commentary Par XXIII 24

The phrase sanza costrutto ('without putting it in words') is a bit unusual.  For more on costrutto, see C.Par.XII.67.  Mattalia (DDP Mattalia.Par.XXIII.24) explains that it means 'the parts and elements of "discourse"' and goes on to suggest that, in De vulgari eloquentia, Dante refers to it as constructio, that is, the building blocks of language.  The word appears four other times in the poem ([Inf XI 30]; [Purg XXVIII 147]; [Par XII 67]; [Par XXIX 31]).  Its use this many times may reflect the fact that it happens to rhyme with tutto.