盂方水方

If the basin is square, the water in it will also be square. (idiom)

basin / wide-mouthed jar or pot

surname Fang

square / power or involution (math.) / upright / honest / fair and square / direction / side / party (to a contract, dispute etc) / place / method / prescription (medicine) / just when / only or just / classifier for square things / abbr. for square or cubic meter

surname Shui

water / river / liquid / beverage / additional charges or income / (of clothes) classifier for number of washes