Commentary for Berakhot 64:9

ANYONE WHO PROLONGS HIS PRAYER AND EXPECTS IT TO BE ANSWERED. When one prays a lengthy t’feeloh and expects to be answered, he will eventually suffer heartache. We are expected to pray and leave the outcome to Hashem. To expect that Hashem will answer our prayer is somewhat pretentious and it has a negative effect. The explanation is: עיון תפלה that will result in heartache occurs when one expects his supplication to be answered because he had proper concentration while he prayed.
Tosfos will now show us that there seems to be a contradiction between two Gemaros about whether עיון תפלה is a valuable component in praying or is it perhaps a negative component as it seems from our Gemara. This is bewildering, for here it appears that concentration while praying is not a constructive component of prayer and so too, it appears in perek HoRo’eh (later 55a) where the Gemara says: Three things cause one sins to be remembered, and the Gemara there says that concentration while praying is one of them. Obviously, that is negative. And in perek M’fanin (Shabos 127a) it does not seem that way. For the Gemara says there that there are six things for which a person benefits from their dividends in this world and among them the Gemara lists concentration while praying. We see that it is a positive component.
Tosfos offers further proof that intent while praying is a positive component. And so too, it appears in perek Get Poshut (Bovo Basro 164b) where the Gemara says: there are three negative things from which a person is not saved each day. In other words, there are three negative things that a person engages in every day, and the Gemara says that one of them is concentration while praying. The explanation of עיון תפלה in the context of that Gemara is that one does not have proper concentration while praying. If so, it appears that concentration while praying is a positive component. This is a contradiction to our Gemara and the Gemara in perek HoRoeh.
And we can answer: that there are two opposite forms of concentration while praying. Although the Gemara uses the same term to describe them, they are opposites. There is the concentration while praying of our Gemara where the person praying is expecting that his supplication will be answered, which is a negative component of prayer, and there is the concentration while praying discussed there in perek M’fanin and in perek Get Poshut that one has proper intent while he prays, which is definitely a positive component of prayer.

I.e. anticipates its fulfilment as a reward for its length.

The word for "hope" is here connected with a root meaning "to pray."