Rabbon Gamaliel called on Chilpa, the son of Caroyna, when the latter
asked the Rabbi to pray on his behalf; and he prayed, "The Lord grant
thee according to thine own heart" (Ps. xx. 4). Rabbi H----, son of
Rabbi Isaac, said, "It was not so; he prayed thus, 'The Lord fulfill all
thy petitions'; for a man often thinks in his heart to steal or commit
some other transgression, and therefore 'The Lord grant thee according
to thine own heart,' is a prayer not to be offered on behalf of every
man." But the answer was, "His heart was perfect before his Creator, and
therefore he did so pray on his behalf."
THE MIDRASHIM, _Midrash Shochar Tov_, 20.