Again the kingdom of heaven is like unto a merchant man, seeking goodly pearls: Who, when he had found one pearl of great price, went and sold all that he had, and bought it.

-Bible (NewTestament)
St Matthew13:45^6.

Alas, alas, who's injured by my love? What merchant's ships have my sighs drowned? Who says my tears have overflowed his ground? When did my colds a forward spring remove? When did the heats which my veins fill Add one more to the plaguey bill? Soldiers find wars, and lawyers find out still Litigious men, which quarrels move, Though she and I do love.

-Donne,John
c.1595^1605  'The Canonization', collected in Songs and Sonnets (1633).

He that is a traveller must have the back of an ass to bear all, atonguelikethetail ofa dog toflatterall, themouthof a hog to eat all what is set before him, the ear of a merchant to hear all and say nothing; and if this be not the highest step of thraldom, there is no liberty or freedom.

-Nashe,Thomas
  The Unfortunate Traveller, or the Life of  Jack Wilton.