"and they shall measure to the cities that are around the slain one": (They measure) from the slain one to the cities, and not from the cities to the slain one. If his head was found in one place, and his body in another, the head is brought to the body. These are the words of R. Eliezer. R. Akiva says: The body (is brought) to the head.
(Devarim 21:3) "And it shall be, the city closest to the slain one": the nearest and not the near ones — whence they ruled: If it were found equi-distant between the two cities, both bring two (distinct heifers [and not one heifer jointly]). These are the words of R. Eliezer. The sages say: One city brings, and two cities do not bring.