Answer not a fool according to his folly, lest thou also be like unto him. Answer a fool according to his folly, lest he be wise in his own conceit. (Prov. 26.4-5)
Two answers to the question of what God was doing before he created the world.
John Calvin, Institutes 1.14.1:
It was a shrewd saying of a good old man, who when some one pertly asked in derision what God did before the world was created, answered he made a hell for the inquisitive, (August. Confess., lib. 11 c. 12.)
Augustine, Confessions, 11.12:
How, then, shall I respond to him who asks, “What was God doing before he made heaven and earth?” I do not answer, as a certain one is reported to have done facetiously (shrugging off the force of the question). “He was preparing hell,” he said, “for those who pry too deep.” It is one thing to see the answer; it is another to laugh at the questioner--and for myself I do not answer these things thus. More willingly would I have answered, “I do not know what I do not know,” than cause one who asked a deep question to be ridiculed--and by such tactics gain praise for a worthless answer.