Deuteronomy 6:6, "These words, which I command you today, shall be on your heart;" means that the commandments and teachings of God should not just be intellectual knowledge or something memorized, but deeply ingrained in your innermost being:

Here's a breakdown of the meaning:

"These words, which I command you today": This refers to the commandments, statutes, and judgments that God has given to the Israelites (and by extension, to believers). It encompasses God's instructions for living a righteous life.
"Shall be on your heart": This is the key phrase. It signifies:

Internalization: The commandments shouldn't be external rules that are merely followed out of obligation. They should become a part of who you are, influencing your thoughts, feelings, and desires.
Love and Affection: The heart is often associated with emotions, particularly love. The verse suggests that obedience should flow from a love for God and a desire to please Him.
Prioritization: When something is "on your heart," it's important to you. It's something you think about often and are deeply concerned with. God's words should hold that place of importance in our lives.
Motivation: Obedience should not be driven by fear of punishment or hope of reward, but by a genuine desire to live in accordance with God's will. When the word is on your heart, you're driven from the inside out.
Transformation: Having the word on your heart will change the way you think and act. It will shape your character and guide your decisions.

In essence, Deuteronomy 6:6 calls for a deep, personal connection with God's word. It's not enough to just know the commandments; they must permeate your entire being and transform your life. They should become the lens through which you view the world and the compass that guides your actions.