Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Prophet (peace and blessings be upon him) used to pray two rak'ahs after Maghrib in which he would prolong the recitation, until the people of the mosque dispersed.
Al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains a narrator, Yahya bin Abd al-Hamid al-Himmani, who is da'if (weak).