What is the ruling on praying four rak'ahs as a Sunnah prayer after Dhuhr, after completing the two rak'ahs of Sunnah prayer?

The time between Dhuhr and Asr is a time for prayer during which supererogatory (nafl) prayers are permissible. It has been reported that four rak'ahs before Dhuhr and four after it are recommended. There is no harm in adding or subtracting from this, because the time before and after the Dhuhr prayer is a time when voluntary supererogatory prayers are legislated, as one wishes. The prayers of the night and day are two by two (rak'ahs).