Q:

phrase origin: "sent packing"

What is the origin of the phrase "sent packing," which is used when someone gets the boot?   I have seen it used a lot but would like to know where it originally came from. 

A:

From Shakespeare's Henry IV, Part I, 1596:

FALSTAFF: Faith, and I'll send him packing

Found here. 

A:

According to the OED, this is related to the transitive sense of to pack oneself meant to leave with your belongings, particularly when dismissed.  It dates from around 1450. 
An intransitive to pack is similarly to depart hurriedly or ignominiously, also from around 1450 in An Alphabet of Tales: 

Þis pure man went vnto his howse & stude at þe dure & askid almos; So þis Peirs bad hym pakk & said he sulde hafe none. 

And with send, as usually used today, from around 1580 in J. Jeffere's Bugbears:

I sent the knaves packinge.