Roger Harper from Walsall, UK wrote:

Dear Rabbi,

When and why did the tradition begin of reclining at the Passover meal? In the book of Exodus it seems that the people were instructed for all time to eat the Passover meal with sandals on their feet and staffs in hand as if ready to move on. So why do we lean, which seems to indicate a lack of readiness to move on?

Dear Roger Harper,

Rather than a tradition, reclining while eating the matzah and drinking the four cups of wine is a halacha. Leaning symbolizes freedom and aristocracy. It is first recorded in the Mishnah (c. 200 CE), but it dates back much farther than that.

Only the Jews in Egypt were commanded to eat in a state of readiness to leave; they were indeed getting ready to leave Egypt. But that command was specific for those people and for that year alone.

Sources:

Tractate Pesachim 99b, 108a