Among the matters in respect of which we gave the Messenger of Allah (may Allah's peace and blessings be upon him) the pledge not to disobey him in any goodness was that we should not scratch our faces, bewail, tear our clothes up, or dishevel our hair (in grief)
Authentic hadithعن أسيد بن أبي أسيد التابعي، عن امرأة من المبايعات، قالت: كان فيما أخذ علينا رسولُ الله صلى الله عليه وسلم في المعروف الذي أخذ علينا أن لا نعصيه فيه: أن لا نَخْمِشَ وجهًا، ولا نَدْعُوَ وَيْلًا، ولا نَشُقَّ جَيْبًا، وأن لا نَنْشُرَ شَعْرًا.
Usayd ibn Abu Usayd At-Tābi'i reported that one of the women who gave the pledge to the Messenger of Allah (may Allah's peace and blessings be upon him) said: "Among the matters in respect of which we gave the Messenger of Allah (may Allah's peace and blessings be upon him) the pledge not to disobey him in any goodness was that we should not scratch our faces, bewail, tear our clothes up, or dishevel our hair (in grief)."
Explanation
The Prophet (may Allah's peace and blessings be upon him) used to take a vow from the female companions when giving him the pledge of allegiance, that they should not disobey him. He forbade them, for instance, from scratching their faces or slapping their cheeks; from wailing which is prohibited; from tearing their clothes; and from disheveling and tearing up their hair. All these acts are forbidden to be done when calamities occur.
Source · Narrated by Abu Daoud
From the Hadith Encyclopedia (hadeethenc.com).