Grund

ground, land (usually as someone's property)

bottom (of a container or a body of water)

reason; motive, cause .mw-parser-output .object-usage-tag{font-style:italic}.mw-parser-output .deprecated{color:var(--wikt-palette-grey-lime-8,olivedrab)}[with für (+ accusative) ‘for something’]

"Es muss einen Grund dafür geben."