In the background of the celebration of Chanuka, we read at the beginning of Miketz, that Yosef remained in prison an additional two years after having successfully interpreted the dreams of the Wine Steward and the Baker. Commentaries teach us that Yosef should have been released from prison then, but was "punished" with the extra time for having asked the Wine Steward to remember him to Par'o and not to forget him.
What about Hishtadlus? Was not Yosef behaving the way one should, by taking the opportunity to help himself, rather than relying upon Divine intervention?
The answer is, usually, yes - one should take opportunities to help oneself - but there are limits. Yosef had explained to the Wine Steward that dreams and what they mean are in the hands of G-d. To follow that statement with a plea for the Wine Steward's help was a missed opportunity to sanctify G-d's name.
It is here that the limit lies. One's efforts must always be in the direction of Kiddush HaShem, never, G-d forbid, in the opposite direction.
Rabbi Ephraim Oshry z"l was asked by a Jew in the Kovno ghetto whether he may purchase a baptismal certificate to help him escape to freedom.
Rabbi Oshry's answer was no. There are limits to hishtadlut. May we be wise enough to know the difference.