'Secret' in the Bible

But he turned back from the sculptured stones that [were] near Gilgal, and he said, "I have {a secret message} for you, O king." And he said, "Silence!" So all those standing in his presence went out,

The ambush [was] sitting [in wait] for her in an inner room. And she said to him, "[The] Philistines [are] upon you Samson!" And he snapped the bowstrings just as flax fiber snaps when it comes close to fire. And [the secret of] his strength remained unknown.