One of the first things that is done when building a house is to dig down and put a permanent foundation. Christ relates this type of building to obeying the commandments of God. He wants us to have a permanent reference to build upon.

Luke 6:46-49 KJV

⁴⁶ And why call ye me, Lord, Lord, and do not the things which I say?

⁴⁷ Whosoever cometh to me, and heareth my sayings, and doeth them, I will shew you to whom he is like:

⁴⁸ He is like a man which built an house, and digged deep, and laid the foundation on a rock: and when the flood arose, the stream beat vehemently upon that house, and could not shake it: for it was founded upon a rock.

⁴⁹ But he that heareth, and doeth not, is like a man that without a foundation built an house upon the earth; against which the stream did beat vehemently, and immediately it fell; and the ruin of that house was great.

We need to be people who are unmoved by this world. The only way we can do that is if we are founded on the firm foundation that is Christ.

S. T. 
I Thessalonians 5:24
"Faithful is he..."