הלכה על פרה 1:1

From the laws of the commandment are that which they, may their memory be blessed, said (Mishnah Parah 1:1) the commandment of the heifer is that it be three or four years old, but if it was [older], it is [also] acceptable. And [that] we do not take a calf and raise her to maturity; but rather a cow (heifer), as it stated (Numbers 19:2), "and they shall take to you a heifer." And [that] that which it states about it "pure" (temimah), is to speak about perfect redness, such that two black or white hairs disqualify it. Even if it was shrunken (other textual variants read, dwarfed, meaning a dwarf), it is acceptable, so long as it is all red - as it does not need to be more perfect than other offerings. And if it had hairs whose roots were red and the tips were another color, it all goes according to the roots. And [so,] he trims the tips with a scissors down to the red.