When we desire to confine our words, we commonly say they are spoken under the rose.

Related:

• Quietly rested under the drums and tramplings of three conquests.
  Sir Thomas Browne (1605-1682) -- Dedication to Urn...
• Our character is what we do when we think no one is looking.
  H. Jackson Browne, P. S. I Love...
• Our destiny changes with our thought; we shall become what we wish to become,
  do what we wish to do, when our habitual thought corresponds...
• The long habit of living indisposeth us for dying. -
  Sir Thomas...
• If what we see is somewhat doubtful,
  how can we believe what is spoken behind our back...
• What song the Sirens sang, or what name Achilles assumed when he hid himself among women.
  Sir Thomas Browne (1605-1682) -- Dedication to Urn...
• The words we use can compound our
  problems...
• Commonly we say a judgment falls upon a man for something in him we cannot abide.
  John Selden (1584-1654) --...
• Our very hopes belied our fears, Our fears our hopes belied;
  We thought her dying when she slept, And sleeping...