Sayyiduna Abdullah bin Mughaffal once heard his son making this supplication: "O Allah! I ask You for Jannat al-Firdaws and such-and-such things." So he said: "Son! Ask Allah only for Paradise and seek refuge from Hell, for I heard the Prophet (peace be upon him) say that there will be some people in this Ummah who will exceed the limits in supplication and ablution."