The Rebbe Rashab was once served noodle soup. He lifted his spoon to eat, but the noodles slipped back into the bowl. After this happened several times, he remarked, “It appears that they are not ready [to be refined].”This story appears trivial, but since nothing in the life of a Rebbe is trivial, it seems that this story holds a deep message.
Otzar Pisgomei Chabad p. 11.
Sometimes a person tries again and again to pursue a certain course of action, and yet he feels like he is treading water. None of his efforts have borne fruit. In that case, he should consider the possibility that perhaps this is Hashem’s way of telling him that now is not the time, and he should pursue a different course of action instead.
This principle seems to apply only in cases of divrei reshus (mundane matters) comparable to eating. However, it would clearly not apply to one who faces obstacles to performing a Mitzvah, such as lighting Shabbos candles, davvenen, and so on, for Mitzvos must be performed even with Mesiras Nefesh, self-sacrifice.
To illustrate this, perhaps the following story (cited here) is relevant:
A couple once came filled with fear to Reb Velvel of Brisk on the day after their wedding. When the groom tried to put the ring on the bride’s finger, the ring fell to the ground, and this happened several times, until he finally succeeded. The couple was concerned that this episode might indicate that the match was not destined to succeed.
Reb Velvel smiled and said, “No, this is incorrect. Rather, when the heavenly voice declares that ‘the daughter of so-and-so will marry so-and-so’ [Sotah 2a], it is also declared when the wedding will take place. Since the exact time had not yet come, the ring fell.”