The Prophet (ﷺ) said, "To get the moustaches cut 'short is characteristic of the Fitra."
Sahih al-Bukhari Book 77, Hadith 105
← Previous Hadith that once the Prophet (ﷺ) was in her house, and an effeminate man was there too. The effeminate man said to `Abdullah, (Um Salama's brother) "0 `Abdullah! If Ta'if should be conquered tomorrow, I recommend you the daughter of Ghailan, for she is so fat that she has four curves in the front (of her belly) and eight at the back." So the Prophet (ﷺ) said (to his wives) "These effeminate (men) should not enter upon you (your houses).

Sahih al-Bukhari Book 77, Hadith 104 Next Hadith → Allah's Messenger (ﷺ) said, "Five practices are characteristics of the Fitra: circumcision, shaving the pubic region, clipping the nails and cutting the moustaches short."

Sahih al-Bukhari Book 77, Hadith 106