The Zohar teaches in Parshas Mekaitz, "And he lifted up his eyes, and saw Benyamin his brother, his motherís son.
Rav Chiya explains from this by discussing the posuk in Proverbs 13, 12, "Hope deferred makes a personís heart sick but desire fulfilled is as a tree of life.
He explains from this that a person should pray to Hashem but then not look to closely
Whether or not his tefillos, prayers are answered or not. Because if he does, he will
only cause himself much heartache and he can become sick from this.
Hope deferred makes the heart sick, is exemplified in yaakov, whoís hope in regard to yosef was deferred for a long time, while "desire fulfilled is a tree of life, is exemplified in the case of Benyamin, in as much as only a short time elapsed between yosefs demand that he should be brought to him and his actual arrival.
If a person truly wants his tefillos to be answered, Rav chiya says,
He should be diligent in his study of the Torah. Not only will this
remove the persons mind from his troubles but through this, his
tefillos will be answered. Rebbe Nachman says in Torah aleph that
there has always been an argument about which is more important,
Torah study or prayer and both sides are correct. Both are important
and they depend on one another. We see here the source for this
teaching in the holy Zohar.