Is a person allowed to make decisions based on “signs” or “omens”?
It’s not necessary to ignore coincidences; they may be meant to attract our attention. But we should have good reasons for any decisions that we make as a result of the coincidences. Being guided by arbitrary “signs” is a violation of the commandment against divination (Lev. 19:26). The “sign” used by Eliezer in Gen. Ch. 24 was evidence that Rivkah was a good person and therefore an appropriate bride for Yitzchak. Testing people based on things that they say or do isn’t like relying on signs. The signs have no logical connection with the conclusions that people draw from them, whereas a person’s words or actions do provide insight into what’s on the person’s mind.