What started as an impromptu dinner thrown together by three aides during President Obama’s 2008 presidential campaign has become a White House tradition.

Starting at sundown Monday night, the president will host the first Passover Seder with friends and staff members in the White House’s Old Family Room, the Washington Post reports.

And even though Obama isn’t one of the “chosen people,” the president still knows how to take part in the most celebrated Jewish holiday in America.

So, for those of you wondering what Passover is, how it’s celebrated, or potentially, how can I impress my girlfriend's family, here are the basics in case you find yourself eating bitter herbs or on a quest for the afikoman tonight.

What is Passover?

The weeklong holiday of Passover circles around the biblical story of the Israelites departure from Egypt outlined in the Hebrew Bible books of Exodus, Numbers and Deuteronomy.

Briefly, after the Israelites experienced decades of slavery in Ancient Egypt, God appeared to the Hebrew prophet Moses and told him to ask the pharaoh to let his people go. Despite many warnings, Pharaoh refused and God punished Egypt with 10 plagues that destroyed the country. After the final and most devastating one killed the firstborn sons of every Egyptian, pharaoh broke down and let the Israelites leave the country. They did so in a hurry (in case pharaoh changed his mind again), without any time to fully bake their bread. Pharaoh did in fact have a change of heart and chased after the Israelites. When the Egyptian forces closed in on them at the Red Sea, God told Moses to lift his staff, which parted the body of water, letting the Israelites through but drowning the Egyptians in their wake.

Why is it called Passover?

The word “Passover” refers to the 10th plague when God “passed over” the homes of the Israelites, and spared their firstborn sons from being killed.

What is a Passover Seder?

The Seders are two traditional meals that take place on the first two nights of the holiday. The word “Seder” comes from the Hebrew word for “order” and the meal reflects that. Throughout the meal, Seder-goers read from a book called a Haggadah, which contains biblical passages, songs and stories. It creates a script of sorts for the entire meal. A Seder plate is typically set in the middle of the table with six foods that symbolize elements of the liberation story. For instance, bitter herbs represent the painful experience of slavery and haroset (a mixture of apples, nuts, raisins, wine and spices) signifies the mortar the Israelites used. Matzah and wine are both staple foods. In fact, getting drunk is an imperative.

What is matzah?

Matzah is a brittle, flat and cracker-like bread eaten at Passover to commemorate what the Israelites ate once leaving Egypt. Throughout the entire holiday, Jews go gluten-free -- they are forbidden from eating any leavened food.

Afikomen?

The afikomen is a fun Seder tradition. At the start of the meal, a piece of matzah is broken off and hidden. Either tucked under the head of the household’s chair or hidden somewhere in the house, children are asked to find it and are rewarded with candy or money.

In President Obama’s case, Herbie Ziskend, one of the staffers who started the White House Seder tradition, hides the afikomen for Sasha and Malia Obama to find.

“My strategy is just to find a creative place and hope the Secret Service doesn’t give any hints,” he told the Washington Post.