Pierre Joris teaches poetry at the State University of New York at Albany. In addition to being a published poet in his own right, he is a respected translator of poetry, twice the recipient of PEN awards for translation. Additional biographical information may be found here:
que dieu vous le rende dans l'autre monde means "that god returns it to you in the other world" in French.
son [sic, should be sen] vada o resti intanto non partirai di qua means something like "begone or remains in the meantime you will not leave here" in Italian. It is a quote from Mozart's opera Don Giovanni http://www.mozart.cat/aries/aria_540b.htm.