What word or phrase does your mother always say?
Old English gad "point, spearhead, arrowhead," from Proto-Germanic *gaido (cf. Lombardic gaida "spear"), from PIE *ghei- (cf. Sanskrit hetih "missile, projectile," himsati "he injures;" Avestan zaena- "weapon;" Greek khaios "shepherd's staff;" Old English gar "spear;" Old Irish gae "spear"). Figurative use is since 16c., probably from the Bible.
1570s, from goad (n.); earliest use is figurative. Related: Goaded; goading.
(Heb. malmad, only in Judg. 3: 31), an instrument used by ploughmen for guiding their oxen. Shamgar slew six hundred Philistines with an ox-goad. "The goad is a formidable weapon. It is sometimes ten feet long, and has a sharp point. We could now see that the feat of Shamgar was not so very wonderful as some have been accustomed to think." In 1 Sam. 13:21, a different Hebrew word is used, _dorban_, meaning something pointed. The expression (Acts 9:5, omitted in the R.V.), "It is hard for thee to kick against the pricks", i.e., against the goad, was proverbial for unavailing resistance to superior power.