—Ezekiel 40:3-4 (NASB)
There are a lot of precise, measured plans and designs documented in Scripture. Examples are Noah’s ark, the tabernacle and all the things in it, the temple and all the things in it, the walls of Jerusalem, and the division of the land of Israel among the tribes. When God provides specifications, He expects them to be followed precisely. Several times in Scripture, when speaking of the future, God shows His messengers how He minutely scrutinizes whether something meets His specifications by measuring them, sometimes with a rod and sometimes a line. It has a dual meaning to teach us that God is holding us accountable for both our overall obedience to His Word as well as to every single, minute detail contained therein.
A line is used to measure very long distances, such as the boundaries of a section of land or a city. We don’t use a line of flax as employed in ancient times, but carry over the line terminology to this day in how surveyors calculate such boundaries with modern telescopic and laser-based tools. It’s use throughout Scripture is a dual teaching of whether or not we’re living within the precisely defined boundaries of God’s Word. Are we living in the place that is righteous, holy, and sanctified by obedience to the rules He has set forth? We’re supposed to be living in a house whose cornerstone is Christ Himself and whose foundation is the Word given through His apostles and prophets.  That’s why the line is sometimes also used as a plumbline to check the integrity of the whole to ensure that it’s not deviating or wavering so as to weaken the rest of our house.
But a surveyor can’t measure very small distances well with a line, and so when taking very fine measurements uses a ruler, or in biblical parlance, a rod. It symbolizes God’s measurement of how well we are in compliance with each individual command of His Law. The rod was also used to measure the integrity and straightness of a wall or that joints fit together properly. Together with the line, it’s a teaching that obedience cannot be compromised at either the macro or micro levels in order to ensure that the whole structure is sound not just in appearance, but in every actual detail down to each individual brick.
I think this has application on more than one personal level. It’s definitely a teaching of the need to hold myself accountable to the whole Word of God. To compromise on even one small point is to endanger the whole of my spiritual walk. But I also believe it speaks of my responsibility to take measurements myself according to the standards of His Word, to be certain that others are in complete compliance with His Word and truly meet the standards they profess both in general and individually. Like the Bereans who measured Paul’s words against God’s Word to confirm the authenticity and truth of the message,  so should we specifically and in general.†††