Sayyiduna al-Bara' bin Azib (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "Whoever prays four rak'ahs before Zuhr, it is as though he prayed those rak'ahs in the tahajjud prayer of that night; and whoever prays four rak'ahs after Isha, it will be like praying four rak'ahs on the Night of Decree (Laylat al-Qadr)."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains Nahid bin Salim al-Bahili, and there are other narrators besides him, whom I did not find anyone mentioning. (Allamah al-Haythami said:) I say: The hadiths transmitted from Sayyiduna Anas (may Allah be pleased with him) and other Companions about praying after the Isha prayer will come later.