Daniel was a Jewish exile who served in the courts of Babylonian and Persian kings; his story and visions are recorded in the book that bears his name.
Daniel 6:10 in the King James Version reads:
Now when Daniel knew that the writing was signed, he went into his house; and his windows being open in his chamber toward Jerusalem, he kneeled upon his knees three times a day, and prayed, and gave thanks before his God, as he did aforetime.
The verse appears in Daniel 6, in the account leading up to Daniel in the lions' den. Read it in context at Daniel 6:10, or the full chapter at Daniel 6. Encyclopedia entry: en.wikipedia.org/wiki/Daniel_(biblical_figure).