Performing two Rak´ah (NAfl) Maghrib prayer after sunset

 222. Mukhtar bin Fulful said: I asked anas bin Malik, about the Nafl (voluntary prayer) after the ´Ars prayer, he repiled: ´´Umar used to his the hands for performing prayer after the ´Ars prayer and we used to perform two Rak´ah after sunset before the Maghrib during the time of the Messenger of Allah salla alayhi wa sallam.´´ I said to him: ´´Did the Messenger of Allah salla alayhi wa sallam perform them?´´ He said: ´´He saw us performing them, but he neither commanded nor forbade us to do so.´´