It refers to living in his redemption. It is about living in peace. The law is fulfilled. That is what Jesus did. Jesus lifted that load. He perfectly obeyed the law; now He offers his obedience to all who trust in him, not in their own acts of fidelity.
1 And he shows how beautiful that law of God is. It is the way of love. He teaches us to walk in the way of love. That is his yoke, it is pleasant because it is the way of salvation.
29 Prenez mon joug sur vous et recevez mes instructions, car je suis doux et humble de cœur; et vous trouverez le repos pour vos âmes.