Yiddish: The entire world rests on the tip of the tongue.

Words have serious consequences in the world, whether for good or ill.
SOURCE: Bernstein, Jüdische Sprichwörter und Redensarten.
Compare Mishlei (Proverbs) 18:21, "Death and life are in the power of the tongue."  Also:

.די צונג פֿאַרפֿירט דעם מענטשן צום גליק און צום אומגליק
Di tsung farfirt dem mentshn tsum glik un tsum umglik.
The tongue brings a person good fortune and misfortune.

SOURCE: Stutchkoff, Der Oytser fun der Yidisher Shprakh

די גאַנצע וועלט שטייט אויף דער שפּיץ צונג.

Di gantse velt shteyt af der shpits tsung.

The entire world rests on the tip of the tongue.