saying -you should give three steps of land- —

 saying -need three steps of land- —

saying -land mahābali three feet- (even without proper sentence formation) —

will accept three feet [of land] —

established them as subservient to him by assuming the form of thrivikrama —

 three steps of land —

three steps —

 three steps of land (from that mahābali) —

land with three steps (taking as alms) —