Mate (drink)
Now the mate is ready to receive the bombilla.  Many people choose to pour warm water into the mate before adding the bombilla, while others insist that the bombilla is best inserted into dry yerba.  Wetting the yerba by gently pouring cool water into the empty space within the gourd until the water nearly reaches the top, and then allowing it to be absorbed into the yerba before adding the bombilla, allows the preparer to carefully shape and "pack" the yerba's slope with the bombilla's filtering end, which makes the overall form of the yerba within the gourd more resilient and solid.  Dry yerba, on the other hand, allows a cleaner and easier insertion of the bombilla, though care must be taken so as not to overly disturb the arrangement of the yerba.  Such a decision is entirely a personal or cultural preference.  The bombilla is inserted with your thumb on the upper end of the bombilla, at an angle roughly perpendicular to the slope of the yerba, so that its filtering end travels into the deepest part of the yerba and comes to rest near or against the opposite wall of the gourd.