Once, Nabi Musa (Alaihis salaam) heard a man making Du’a fervently. He (Nabi Musa) said: “O my Rabb! If I had the power. I would have fulfilled his need.” Allah Ta’ala revealed to Musa (Alaihis salaam): “O Musa! He has sheep, and his heart is with his sheep. I do not accept the Du’a of a servant who calls Me whilst his heart is elsewhere with others besides Me.” Nabi Musa (Alaihis salaam) informed the man of this revelation. He them applied his heart fully to Allah Ta’ala, and his need was fulfilled.