The ark that Noach built was enormous. But it was also far too small.
The Torah gives its dimensions precisely: 300 cubits long, 50 cubits wide and 30 cubits high, making it approximately 530 feet long according to Rav Moshe Feinstein's measurement of a cubit.
Inside, Noach was to shelter his family, representatives of the animal kingdom and enough food to sustain them throughout the Flood.
But how could they possibly all fit?
The Ramban (Rabbi Moshe ben Nachman, 1194-1270), commenting on Genesis 6:19, asks this very question. Given the number and size of the animals, not to mention the food they required, even ten arks of those dimensions would not have been enough.
Clearly, he explains, a miracle took place and "the small contained the great". The ark held more than its physical space could ordinarily accommodate.
And that leads the Ramban to raise a second question, one that goes to the heart of what Hashem expects of each of us.
If the animals could only fit through a miracle, why did Noach have to build such a large ark in the first place? Why spend years constructing an enormous vessel when Hashem could just as easily have made a small one hold everything?
The Ramban gives two answers.
First, the size of the ark ensured that people would notice it. Imagine the scene: Noach cutting timber, assembling beams and building a towering structure, day after day. Neighbors would stop and stare. They would ask what he was doing, and he would have an opportunity to warn them of the coming destruction.
Perhaps, the Ramban suggests, the sight of the ark would move them to repent.
Even as the Flood approached, Hashem was giving humanity another opportunity to change its ways. The ark was not merely a refuge for Noach and his family. Its construction was itself a warning to everyone else.
Noach had a duty not only to prepare for his own survival, but to give others the chance to save themselves.
The Ramban's second answer is no less significant.
Hashem commanded Noach to build a large ark in order to reduce the extent of the miracle needed to save those aboard.
The Ramban explains that this is the pattern of miracles throughout the Torah and the Prophets: human beings must do whatever lies within their power, and what remains is left in the hands of Heaven.
This establishes an important principle: Divine intervention does not absolve human beings of responsibility.
Hashem could have preserved Noach and the animals without an ark at all.
Instead, He ordered Noach to get to work.
Noach could not make the animals and their provisions fit into the ark by ordinary means. But he could build the decks, gather supplies and construct a vessel large enough to accommodate as much as possible.
The Ramban's two explanations are not as different as they first appear.
In the first, Noach's efforts might persuade others to repent. In the second, his efforts reduce the miracle needed to preserve life.
In both cases, Hashem chooses to make human action part of a process that He could accomplish without it.
We often hesitate to act when the task before us seems impossibly large. What difference can one person make? What good is one more effort when the odds are so overwhelming?
Consider the challenge of confronting antisemitism or countering the lies that are told about Israel. No individual can guarantee that speaking out will change minds, let alone turn back a rising tide of hatred.
But if the enormity of the problem becomes an excuse for silence, we have misunderstood the Ramban's lesson.
The Ramban does not promise that every effort will succeed. He insists that we remain obligated to act even when success depends on forces beyond our control.
Noach could not have saved the animal kingdom through his own efforts. His ark, however large, would never have been sufficient.
Yet that did not excuse him from building it.
He did not wait for the miracle before picking up his tools.
Neither should we.
We must build the ark. The rest is in Hashem’s hands.