anything else—that is oppression; so if you invoke Allah against the wrong-doer, Allah will answer your supplication. Even if the oppressed person is an unbeliever whom you have treated unjustly and he then calls upon Allah, Allah will answer him—not out of love for the unbeliever, but out of love for justice. The oppressed must be given redress against the oppressor. For this reason, when the Prophet (peace and blessings be upon him) sent Mu‘adh to Yemen he said, “Beware the supplication of the oppressed, for between it and Allah there is no barrier.” Thus, the prayer of the oppressed is answered when he invokes against his oppressor in proportion to, or less than, the wrong done to him; but if he exceeds that limit he becomes the aggressor, and his supplication will not be answered.

That is the first.

The second is the supplication of the traveler. When a traveler asks Allah to facilitate his journey, assist him in it, or makes any other request, Allah—exalted is He—answers him. Therefore one should seize the opportunity to pray while traveling; and if the journey is one of obedience, such as for ‘umrah or ḥajj, this only strengthens the likelihood that the prayer will be answered.

The third is the supplication of the parent. In some versions of the hadith it is stated “against his child,” while in others it is left unrestricted—“the parent”—meaning whether he prays for his child or against him, and this is