John Calvin Commentary Genesis 11:3

"And they said one to another, Come, let us make brick, and burn them thoroughly. And they had brick for stone, and slime had they for mortar." — Genesis 11:3 (ASV)

And they said one to another. That is, they mutually exhorted each other; and not only did each person earnestly put their own hand to the work, but they also impelled others to the daring attempt.

Let us make brick. Moses intimates that they had not been persuaded to begin this work because of the ease with which it could be accomplished, nor because of any other advantages that presented themselves. Instead, he shows that they had struggled with great and arduous difficulties, by which means their guilt became all the more aggravated.

For how is it that they exhaust and wear themselves out in vain on a difficult and laborious undertaking, unless it is because, like madmen, they rush impetuously against God?

Difficulty often deters us from necessary works; but these men, when they had neither stones nor mortar, still did not hesitate to attempt the raising of a structure that might transcend the clouds.

We are taught therefore, by this example, to what lengths human lust will hurry people when they indulge their ambition. Even a secular poet is not silent on this subject, —

“Man, rashly daring, full of pride,
Most covets what is most denied.”
And a little afterwards, —
“Counts nothing arduous, and tries
Insanely to possess the skies.”