Bulugh al-Maram 2 The Book of Prayer كتاب الصلاة 231

وَفِي رِوَايَةٍ لِلْبُخَارِيِّ : { فَلْيُتِمَّ , ثُمَّ يُسَلِّمْ , ثُمَّ يَسْجُدْ } . 1 1 – صحيح . رواه البخاري ( 1 /504 / فتح ) .

And in the narration of al-Bukhari: ‘he should complete (the prayer) then he should say Taslim and then perform the prostration’.