Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: "The Messenger of Allah (peace and blessings be upon him) recited in some prayers and remained silent in some prayers," so we recite in those in which the Prophet (peace and blessings be upon him) recited, and we remain silent in those in which he (peace and blessings be upon him) remained silent. It was said to him: "Perhaps the Prophet (peace and blessings be upon him) recited within himself (silently)?" He became angry and said: "Is the Messenger of Allah (peace and blessings be upon him) to be accused? Is the Messenger of Allah (peace and blessings be upon him) to be accused?"
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11955