Explanation: Without Tefilah ...

Proof: Since Moshe Rabeinu a.h. had many good deeds to his credit, yet he still needed Tefilah.

Clarification: This mean that he expects his request to be answered because he prayed sincerely.

Question: Here and in Perek ha'Ro'eh (Daf 55.), where the Gemara cites three things that evoke a person's sins; one of them - 'Iyun Tefilah'; it implies that Iyun Tefilah is not a good thing

Implied Question #1: This is not the case in Perek Mefanin (Shabbos, 127.) where it lists 'Iyun Tefilah' as one of the things for which a person receives the fruit of his labors in this world ... , implying that it is a good thing?

Implied Question #2: And likewise, in 'Get Pashut' (Gitin 164:) where the Gemara lists one of the three things from a person cannot escape as 'Iyun Tefilah' (meaning that one fails to concentrate on one's Tefilah) ...

Conclusion: Implying that it is good?

Answer: There are two kinds of 'Iyun Tefilah': The one in our Sugya, where a person expects his Tefilah to be answered (as we explained earlier), and the one there (in the latter two Sugyos), which refers to someone who Davens with concentration.

Clarification: Rashi explains that Rebbi Elazar extrapolated this from the fact that the Pasuk does not say "and my tears you shall see' - a proof that they can be seen all the time, and one needs only to Daven that they should be accepted.

Halachah: That explains as to why the Chachamim instituted specifically this Pasuk before "Tehilah le'David".

Conclusion: To the preclusion of those who recite various 'Ashrei's'.