"and she shall spit in his face": I might think "in his face," literally; it is, therefore, written "before the eyes of the elders" (so that "in his face" is understood as "before him.")
"and she shall answer and she shall say": "answering" is written here and elsewhere (Ibid. 27:14). Just as there, in the holy tongue, so, here.
"Thus shall it be done with the man": From here it was ruled: If she removed the shoe and spat, but did not recite (the prescribed formula), the chalitzah is valid. If she recited and spat but did not remove the shoe, the chalitzah is invalid. If she removed the shoe and recited but did not spit — R. Eliezer says: The chalitzah is invalid; R. Akiva says: The chalitzah is valid. R. Eliezer said to him. (It is written) "Thus shall it be done" — Everything which is an act is a categorical requirement. R. Akiva: Is that a proof? It is written "with the man" — Everything that is done with the man (such as the removal of the shoe) is a categorical requirement.