"And they shall eat the meat on that night, roasted over the fire, together with matzah; with bitter herbs they shall eat it"—Exodus 12:8.
We are commanded to eat the Paschal Offering on the eve of the fifteenth of Nissan [the first night of Passover], according to all the requirements detailed in the Torah: it must be roasted, eaten all in one home, and accompanied by the consumption of matzah and bitter herbs.