Just for record and the OP's benefit:
se16teddy on wordreference forum (cited by ThirdNews on this page):
The OED gives the following examples of do being added to an imperative for emphasis (meaning 30b of the verb do).
'1611 SHAKES. Wint. T. V. iii. 144 Giue me the lie, do. 1775 SHERIDAN Duenna II. iv, Get in, do. 1838 DICKENS O. Twist lii, Let me say a prayer. Do! 1930 D. L. SAYERS Strong Poison ix. 112 'Ev another crumpet, do, Mr. Bunter.'
When used these days, it in normally intended to suggest an archaic or unduly refined speech pattern.
AHD 2000 cited in TFD:
v.intr. 6. Used after another verb for emphasis: Run quickly, do!