Al-Haytham ibn Kulayb narrated it in his Musnad with a good chain of transmission, as stated in Ādāb al-Zifāf (pp. 203–204, new edition).

A point of benefit: al-Ḥāfiẓ said in al-Fatḥ (10/372–373): “His words, ‘women who create gaps between their teeth for beautification,’ indicate that the blameworthy woman is the one who does this for the sake of beautification. If she needs it for treatment, for example, then it is permissible. His words, ‘those who alter Allah’s creation,’ are an inherent description of those who practise tattooing, pluck facial hair, and create gaps between the teeth; and likewise of those who add hair extensions, according to one of the narrations.”

Al-ʿAynī said in ʿUmdat al-Qārī (22/63): “His words, ‘those who alter the creation of Allah, Most High,’ are like an explanation of why they deserve to be cursed.”

Once you know the foregoing, the invalidity of Shaykh al-Ghumārī’s statement in his treatise Tanwīr al-Baṣīrah bi-Bayān ʿAlāmāt al-Kabīrah (p. 30) becomes clear: “I say: Altering Allah’s creation applies to what leaves a lasting effect, such as tattooing and creating gaps between the teeth, or what disappears only slowly, such as plucking facial hair. Shaving the beard, however, does not constitute altering Allah’s creation, because the hair appears again on the second day after it is shaved…”

I say: This is a false statement for several reasons. First, it is a mere assertion for which there is no evidence from the Quran, the sunnah, or reports from the early generations. It has long been said: “Claims, unless you produce evidence for them, leave their proponents as mere claimants.”

Second, it contradicts what is indicated by the additional wording, “those who add hair extensions.” Hair extensions are not like tattooing and the like, whose effects do not disappear, or disappear only slowly—especially when they are of the type known today as a wig, which can be removed quickly, like a cap.