ויצא יצחק לשוח בשדה לפנות ערב… (חי שרה כד: סג)

The Gemara (ברכות לד:ב) teaches that one should not daven in an open area but rather in a place surrounded by walls. ויצא יצחק לשוח בשדה – So why did Yitzchak go outside to daven in the fields? The three daily tefillos (Shacharis Mincha and Maariv) should ideally be prayed in a Beis Medrash.  However, aside from these designated prayers, a person must be accustomed to speaking to Hashem anywhere.  They can request whatever they need in their own language at any time.  This is why the pasuk says: ויצא יצחק לשוח בשדה – Yitzchak went out to “shmooze” and speak to Hashem.  This type of prayer can be recited anywhere.