Windows of Heaven
According to Ecclesiastes 3, there is a time to every purpose under heaven. But what does the word “time” mean in context to God’s purpose? Time is more than a number on a clock, or the hours that define a day. A better interpretation of time would be “opportunity.” For every purpose, there is an opportunity for things to occur.
The opportunity for an optimal space launch has a beginning and an end, and is called a “launch window.” So it is with the “windows of heaven” referred to in Malachi 3:10. God’s windows of heaven are spans of opportunity that is optimal for His blessing being poured out.