Musnad Abu Ya'la al-Mawsili 148:36

Ishaq ibn Abi Isra'il narrated to us, Hammad ibn Zayd narrated to us, Hanzalah ibn 'Abdullah narrated to us, from Anas, that the Prophet (peace and blessings of Allah be upon him) performed Qunut in the morning prayer after the bowing (ruku'). He said: I heard him supplicating in his Qunut against the disbelievers. He said: And I heard him saying, "And make their hearts like the hearts of disbelieving women."