Green’s Dictionary of Slang

dig up v.²

to leave.

1923		J. Manchon Le Slang.
1981		N. Farki Countryman Karl Black 5: Yes, time to dig up from this place.
1986		R. Hewitt White Talk Black Talk 154: In school, if a teacher gets on your nerves and they don’t know what you’re talking about, and you tell ’em to, say, ‘dig up’ or something, they don’t know what it means but you know what it means.