Musnad Ahmad 25:488

Abdullah narrated to us, Ubaydullah ibn Umar narrated to us, from Za'idah ibn Abi al-Ruqad, from Ziyad al-Numayri, from Anas ibn Malik, who said: When the Prophet, peace and blessings of Allah be upon him, would enter Rajab, he would say: "O Allah, bless us in Rajab and Sha'ban, and bless us in Ramadan." And he used to say: "The night of Friday is radiant, and its day is bright."