'Secret' in the Bible

But Ehud himself turned back from the sculptured stones at Gilgal, [and he returned to Eglon] and said [to him], “I have a secret message for you, O king.” Eglon said “Keep silence.” And all who attended him left him.

Now she had men lying in ambush in an inner room. And she said to him, “The Philistines are upon you, Samson!” And he broke the cords as a string of tow breaks when it touches fire. So [the secret of] his strength was not discovered.