My father tried to keep the matter from me, but I found out.
It would be best to keep the matter to himself.
She'd asked him to keep the matter to himself and not expect anything to come of it.
But local political leaders often keep such matters under their own control.
However, it is important for us all to keep the matter in context.
We must be very careful to keep the matter to ourselves.
The Dwarf could not understand it, but decided to keep the matter to himself.
"All the same, we will keep matters as they are."
If no one knew us we can keep the matter to ourselves.
It seemed best to keep matters in my own hands.