parshanut torah comment - When Yaakov said "whoever stole the idols will not live", was that a curse or vow?

In this week's parsha (Bereishit 31:32), Yaakov says that whoever stole Lavan's idols will not live, not knowing that Rachel had taken them.

The question is, was this said as a curse or a neder (vow)? Because if it was a neder, he could have had it annulled, with the easy out of "i didn't know it was my favorite wife". And if it was a neder, why didn't he have it annulled?

Answer

Rashi to the cited verse:

לא יחיה: ומאותה קללה מתה רחל בדרך

Shall not live: and from that curse Rachel died on the road.

So it seems that it was a curse.