Final answer:
In the Bible, it is God who passes through the pieces to seal the covenant with Abraham.
Step-by-step explanation:
In the Bible, it is God who passes through the pieces to seal the covenant with Abraham. In Genesis 15:17-18, it is described how God appeared to Abraham in a vision and passed between the halves of a sacrificial animal, symbolizing the binding agreement between God and Abraham. This act signifies God's commitment to fulfilling His promises to Abraham and his descendants.