John Calvin Commentary Isaiah 22:9

"And ye saw the breaches of the city of David, that they were many; and ye gathered together the waters of the lower pool;" — Isaiah 22:9 (ASV)

And you have seen the breaches. He continues his narrative, for during prosperity and peace, no one cares about fortifications or instruments of war. It is necessity alone that stirs people and makes them active; peace and quietness make us lazy and cowardly. As long as they thought they were far from danger, they ignored the breaches in the wall; but when news of war came, they became anxious about them and began to make arrangements to prevent the enemy from entering.

Of the city of David. By “the city of David,” he means the inner part of the city; for, like many other cities we see, the city was divided into two parts. The whole of Jerusalem was surrounded by walls and ramparts, but the inner part was more strongly fortified and was called “the city of David.” The Temple was later fortified, and as a result, the city could be said to consist of three parts.

Isaiah means that the Jews had nearly despaired of the safety of the whole city when they retreated to the innermost and best-fortified part of it. Indeed, it is evident from sacred history that the situation was desperate.

Therefore, we may also infer that the prophecies were not collected in regular order, and that those who compiled them into one volume did not arrange them chronologically.

The waters of the lower pool. He adds that water was collected for essential purposes, so that the besieged would not lack it, and that the pool served as cisterns.