Genesis 29:28 narrates Jacob marrying both sisters Leah and Rachel, the exact scenario this law forbids.

Genesis 30:15 shows the rivalry between sisters Leah and Rachel as co-wives, fulfilling the very conflict this law aims to prevent.

Genesis 29:27 recounts Jacob marrying both Leah and Rachel—the very practice Leviticus later prohibits as taking a sister as rival.

In Genesis 31:50, Laban forbids Jacob from taking additional wives beyond his two sisters, paralleling the prohibition against rival sisters.

Malachi 2:15 grounds marriage in unity and godly offspring, reinforcing why taking a sister as rival violates the marital ideal.

1 Samuel 1:6-8 depicts Peninnah provoking Hannah as a rival wife, but they are not sisters — a thematic parallel to co-wife rivalry.