Sayyiduna Anas (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Four rak'ahs (sunnah) before Zuhr are like praying the same number after Isha, and four rak'ahs (sunnah) after Isha are equal to praying the same number on Laylat al-Qadr (the Night of Decree)."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains a narrator, Yahya bin Uqbah bin Abi al-Ayzar, who is extremely da'if (weak). A similar report from Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) has already passed in the chapter on praying after Zuhr.