Reference for Berakhot 109:2

הא לא קשיא הא דמעיין בה הא דלא מעיין בה והיכי עביד דמפיש ברחמי

There is no contradiction ; the latter refers to where one calculates [on the prolongation of his prayer], the other to where he does not calculate upon it. So how should one act ? He makes many supplications.

Jastrow