Sayyiduna Abdullah bin Abi Qatadah narrates from his father (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) used to recite in the first two rak'ahs of the Zuhr prayer, making the first rak'ah long and the second rak'ah short, and he (peace and blessings be upon him) used to do the same in the Fajr prayer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2484