All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is desirable for the Imaam when he finishes the prayer and says Astaghfiru Allaah three times to turn his face towards the congregation. This is because Samurah ibn Jundub said: ‘‘When the Prophet would have finished leading us in prayer, he would turn his face towards us.’’ [Al-Bukhari]
Moreover, Al-Bukhari entitled a chapter in his book: The chapter of the Imaam turning his face towards the congregation after finishing the prayer by saying Assalaamu ‘Alaykum.
Allaah Knows best.