Numbers 35:31-34

CKJV_Strongs(i)
  31 H3947 Moreover you shall take H3724 no satisfaction H5315 for the life H7523 of a murderer, H7563 which is guilty H4191 of death: H4191 but he shall be surely H4191 put to death.
  32 H3947 And you shall take H3724 no satisfaction H5127 for him that is fled H5892 to the city H4733 of his refuge, H7725 that he should come again H3427 to live H776 in the land, H4194 until the death H3548 of the priest.
  33 H2610 So you shall not pollute H776 the land H1818 where you are: for blood H2610 it defiles H776 the land: H776 and the land H3722 cannot be cleansed H1818 of the blood H8210 that is shed H1818 in it, but by the blood H8210 of him that shed it.
  34 H2930 Defile H776 not therefore the land H3427 which you shall inhabit, H8432 where H7931 I live: H3068 for I the Lord H7931 live H8432 among H1121 the sons H3478 of Israel.