yes, cutting the grass (or pulling it from the ground when possible, if it is long enough to get a good hold of.
The idea is
1) To make sure there is a wide enough area to build a fire without fear of it spreading across ground vegetation
2) To pull/cut enough grass to start a small fire (and hopefully keep it burning for a while)
3) To clear a large enough area so that it is relatively easy to spot predators from getting too close before we spot them