Midrash su Giudici 16:4

(Ib. 16, 4) And it came to pass after this, that he loved a woman in the valley of Shorek, whose name was Delilah. We are taught that Rabbi says: "Even if she were not called Dalilah, she desired that name because she weakened his strength, she weakened his heart, she weakened his deeds." That she weakened his strength we infer from the following passage (Ib., ib. 19) And his strength departed from him; that she weakened his heart we find in the following passage (Ib., ib. 18) And when Delilah saw that he had told her of his heart, etc. How did she know it? Said R. Chanan in the name of Rab: "Truth is recognized in its distinction." Abaye said: "She was sure that this righteous man would not utter the Holy name in vain. Therefore when he said I am a Nazarite of God, she believed him."