First, unless the Lord... (1-2). Life is from the Lord. We live our lives for the Lord. Apart from him all of our labor is in vain. Many people seek to accumulate wealth or power in this world. But the legacy of the life apart from the Lord is perishable. It is a cursed life, toiling for food to eat but ending in death. There is no rest in such a life, for the end is to be laid in the dust of the ground. God is our creator. He builds his people into the house of God to reveal himself. When we yield ourselves to the Lord he uses us and blesses us with the assurance that this life is not in vain, but a precious building block of his eternal glory. Second, sons are a heritage from the Lord (3-5). Children are a gift from the Lord. They are truly a blessing, and they belong to him. They are a part of what God is building. When we live as stewards of God's life in them, we know that we are blessed. They will never be put to shame, for they belong to the Lord, a part of his house and his kingdom.
Application: Lord, make me a part of your house and your eternal kingdom. Use me as you will.
One Word: The Lord builds the house