When I was looking at this passage, and the Collegeville Bible commentary on it, it struck me that the commandment Moses is bringing to the people is to love God. Can love be commanded?
Here is the passage from the Rite of Penance, number 106:
In those days
Moses said to the people:
“Hear, O Israel! The Lord is our God, the Lord alone!
Therefore, you shall love the Lord, your God,
with all your whole heart,
and with all your soul,
and with all your strength.
Take to heart these words which I enjoin on you today.
Drill them into your children.
Speak of them at home and abroad, whether you are busy or at rest.
Bind them at your wrist as a sign
and let them be as a pendant on your forehead.
Write them on the doorposts of your houses and on your gates.
The Franciscan Scripture scholar Leslie Hoppe explains that the Israelite understanding of love in this context is tied up closely with obedience. The Chosen People have an experience of liberation, a relationship with the One God. They owe no loyalty to any other god. The singular focus of their covenant with the One God has a consequence: pour all of what they have into the relationship. This relationship encompasses all feelings, all religious devotion, every fiber of their being. It includes the current and the future generations.
This reading seems good for form II, when a preacher can deliver the message of a communal commitment to God. The Christian consequence is that we have heard Jesus’ affirmation of the Greatest Commandment (Cf. Matthew 22:36-37, Mark 12:28-30) and we are prepared to adhere to a total commitment to Christ and to his Gospel.
It might seem a no-brainer to include this Matthew passage (RP 51) or Mark’s (RP 187) along with this selection from the Pentateuch. But I think a pairing with a Gospel reading that describes the extravagance of God’s love would be equally effective.
The bottom line is that God loves us deeply. Our response to this love is advised, urged, commanded (if you will) to be as deep as we can muster.