Wa alaykum salam wa rahmatuLlahi wa barakatuHu,

There are two established rak’ahs before the zuhr prayer from the ten rawatib that should accompany the five daily prayers. These first two are emphasized [sunnah mu’akkadah]; and one may add two more if one wants they are encouraged [sunnah]. (Nihayat al-Muhtaj 2/108, 110; Rawdat al-Talibin 1/327) If one does pray the four rak’ahs before zuhr, then making a taslim between them is sunnah. (Sharh al-Muhadhdhab 4/10)

And Allah knows best.

Shafiifiqh.com Fatwa Dept.