Appears 3 times in the Quran. (Root: علم)
  1. They said: Certainly you know that we have no claim on your daughters, and most surely you know what we desire.

  2. He said: Truly you know that none but the Lord of the heavens and the earth has sent down these as clear proof and most surely I believe you, O Firon, to be given over to perdition.

  3. Then they were made to hang down their heads: Certainly you know that they do not speak.