يُعِيدُ رَكْعَةً وَاحِدَةً[1].
Hadith.1200 - Ubayd ibn Zurarah reported from Imam Jafar ibn Muhammad Al-Sadiq (as) regarding a man who joined the prayer with the Imam but had missed one rak'ah. After the Imam concluded the prayer, he left with the people and then remembered that he had missed a rak'ah. Imam (as) said: "He should perform one rak'ah”.