Which preposition to use with tenuous

as Occurrences 1%

Leonora would have wished that the night should never end; that the waning moon, which seemed to have been slashed by a sword, should stop eternally in the sky to wrap them forever in its feeble, dying light; that the river should be endless, and the boat float on and on until, overwhelmed by so much love, they should breathe the last gasp of life away in a kiss as tenuous as a sigh.

Which preposition to use with  tenuous