The verse "The days of Isaac were one hundred eighty years" from Genesis 35:28 is a simple statement of fact. It means Isaac, the son of Abraham and Sarah, lived to be 180 years old. It's a closing summary of his lifespan, placed at the end of the account of his life and family events.

Here's what we can infer from this seemingly straightforward verse:

Isaac lived a long life: In ancient times, and especially as portrayed in Genesis, living to a great age was often seen as a blessing from God. 180 years was a significant lifespan, even within the longer lifespans attributed to people in the early chapters of Genesis.
Chronological marker: It provides a chronological marker in the biblical narrative, helping to place events in relative time.
End of an era: It marks the end of Isaac's story within the larger narrative of Genesis. The focus then shifts more squarely onto his sons, Jacob (Israel) and Esau, and their descendants.

In short, the verse is a concise summation of Isaac's life, highlighting its length and signaling a transition in the Genesis narrative.