It is mentioned in Tafsir Imam Hasan Askari (a.s.) that when Quraish forced Bani Hashim to take refuge in the defile of Abu Talib, the Quraish appointed some persons to guard the entrances so that they may prevent rations from them. Companions of the Prophet were reduced to the greatest distress; they were miraculously relieved by the Prophet, Allah sending them better supplies than the manna and quails provided for the Bani Israel.
And all got what they so desired. They once complained about their confinement in the defile and the Holy Prophet (S) signaled to the walls of the defile to move further and a huge field appeared in the defile. Then the Holy Prophet (S) signaled with his hands to the desert to throw up miraculous vegetation and streams of water etc. Then Bani Hashim complained to the Prophet that their clothes had become old and soiled.
He commanded them to breathe on them, draw their hands over them in putting them on, and pronounce blessings on him and his sacred family, by which means their garments were rendered white, clean, and becoming, and their grief and trouble were removed, and their persons moreover were thus perfectly cleansed.
They exclaimed, “How wonderful it is that by pronouncing blessings on you and your family, our garments and persons should become so pure!” He replied, “This likewise purifies your hearts from hypocrisy, enmity, and everything bad, and washes out the record of your sins more entirely than the soiling of your garments.”