Countdown to Pesach 26: A Meal of Hallel
We differentiate between Hallel that is recited as a Minhag – Custom and a Hallel that is recited as a Chiyuv – Obligation. The Hallel of Rosh Chodesh is a custom, (Ta’anit 28b) which is why we may take a break in middle of Hallel without having to go back to the beginning. (Magen Avraham O”H 422:10) However, if one takes a long break in middle of reciting an obligatory Hallel, he must go back to the beginning. The Hallel of Pesach night is obligatory. (Pesachim 95b) How can we take such a long break in middle of Hallel in the Hagaddah? We recite two paragraphs before the Matzah, Marror, Korech and the meal, and only complete the Hallel after we eat.
We can understand that the Mitzvot we perform are actually part of the Hallel, and they are not considered a break. Halacha is telling us that the meal too, must be an expression of Hallel. Our meal must be a celebration of the miracle of the Redemption. (Machberes Avodas Hashem)