Who is left that is old enough to have seen the previous temple which was destroyed by the Babylonians 66 years before? The first temple, the temple of Solomon was destroyed in 586 BC (2 Kings 25:13-17); it is now 520 BC. Some were old enough to remember when the work began, as Ezra 3:12 tells us, and had wept with a loud voice when the foundation of this new temple was laid, because of its reduction in size and glory.
We can relate to that problem, because we serve the Lord in what is often called a day of small things. We read about mighty revivals, awakenings, wonderful things taking place in the past, and we are in an atheistic land where conversions come in very much smaller numbers. It is nothing, by comparison to a time of revival, and we become despondent. Many people will give up: ‘Let's just pray for revival. It is not worth doing anything other than that.’ The equivalent is happening here with the Jews of old.