(Devarim 22:17) "And they shall spread the garment before the elders of the city": They must clarify the matter as a (new) garment. The witnesses for both husband and father must clarify the matter before the elders of the city. This is one of the things that R. Yishmael was wont to expound as a mashal (a metaphor). Similarly, (Shemoth 22:2) "If the sun shone upon him": Now is it upon him alone that the sun shines? What, then, is the intent of "If the sun shone upon him"? Just as the sun is "peace" for the world, here, too, if he (the one threatened with robbery) knows that he (the robber) is "at peace" with him (and will not kill him if he resists, [as in the instance of a father robbing a son]) and he (the son) kills him, he is liable (for murder). Similarly, (Ibid. 21:19) "If he arise and walk outside on his crutch" — on his own power.

And thus: "And they shall spread the garment before the elders of the city" — If the witnesses of the husband were (clearly) found to be zomemin (scheming witnesses), etc.

R. Eliezer says: The words ("and they shall spread the garment") are to be taken literally (as signifying the nuptial garment).