From Infinity War #6, the conclusion of a Marvel Crisis Crossover. Galactus shuts down Thanos in a way only a cosmic being could:
Galactus: "Silence, fool! Mighty Galactus knows what must be done!"
Thanos: "Does mighty Galactus know that our chances of outrunning this disturbance are minimal?"
Galactus: "Does annoying Thanos have an alternative course of action to suggest?"
Galactus: "Then let silence reign."