Sunan Abi Dawud, Hadith 1027

This traditions has also been narrated by Muhammad b. Muslim al-Zuhr through a different chain of transmitters and to the same effect. This version adds; He should perform two prostrations before giving the salutation.

حَدَّثَنَا حَجَّاجٌ، حَدَّثَنَا يَعْقُوبُ، أَخْبَرَنَا أَبِي، عَنِ ابْنِ إِسْحَاقَ، حَدَّثَنِي مُحَمَّدُ بْنُ مُسْلِمٍ الزُّهْرِيُّ، بِإِسْنَادِهِ وَمَعْنَاهُ قَالَ ‏ "‏ فَلْيَسْجُدْ سَجْدَتَيْنِ قَبْلَ أَنْ يُسَلِّمَ ثُمَّ لْيُسَلِّمْ ‏" ‏ ‏.‏

sunnah.com