Sayyiduna Abu Umamah bin Sahl bin Hunaif (that is, As'ad) used to say: My father performed ghusl at Kharrar (a place near Juhfah), so he took off his cloak, and Sayyiduna Amir bin Rabi'ah was watching, and Sayyiduna Sahl was fair-skinned. Sayyiduna Amir bin Rabi'ah, upon seeing him, said: I have never seen a man like you, nor the skin of any virgin woman. Immediately, Sayyiduna Sahl developed a fever, and it was a severe fever. Then someone came to the Messenger of Allah (peace be upon him) and informed him that Sayyiduna Sahl had developed a fever, and now he would not be able to go with you, O Messenger of Allah (peace be upon him). So the Messenger of Allah (peace be upon him) came to Sayyiduna Sahl, and Sayyiduna Sahl related what Sayyiduna Amir bin Rabi'ah had said. Upon hearing this, the Prophet (peace be upon him) said: "Will one of you kill his brother? (And to Sayyiduna Amir he said) Why did you not say «بَارَكَ اللّٰهُ» ? (That is, may Allah bless, or 'Masha Allah la quwwata illa billah' as in another narration). The evil eye is true. Perform wudu for Sahl." Then Sayyiduna Amir performed wudu for Sayyiduna Sahl (this is mentioned in another hadith), after which Sayyiduna Sahl recovered and went with the Messenger of Allah (peace be upon him).