Narrated Abu Huraira:
Allah's Apostle said, "The Hour will not be established until the son of Mary (i.e. Jesus) descends amongst you as a just ruler, he will break the cross, kill the pigs, and abolish the Jizya tax....
In the Name of Allah we enter, in the Name of Allah we leave, and upon our Lord we depend [then say As-Salaamu 'Alaykum to those present].
Info: Abu Dawud 4/325. Muslim {Hadith no. 2018) says that one should mention the Name of Allah when entering the home and when beginning to eat; and that the devil, hearing this, says: "There is no shelter for us here tonight and no food".