Rashi on Numbers 13:27/רש"י על במדבר י״ג:כ״ז

1זבת חלב ודבש [WE CAME INTO THE LAND … AND SURELY] IT FLOWETH WITH MILK AND HONEY — They stated this because no fabricated statement in which one does not say at least some true words at first can in the end be maintained (Sotah 35a).