Numbers 23:19-20

ASV_Strongs(i)
  19 H410 God H376 is not a man, H3576 that he should lie, H1121 Neither the son H120 of man, H5162 that he should repent: H559 Hath he said, H6213 and will he not do H1696 it? Or hath he spoken, H6965 and will he not make it good?
  20 H3947 Behold, I have received H1288 commandment to bless: H1288 And he hath blessed, H7725 and I cannot reverse it.