I had a hanging lock of hair. My mother said to me: I shall not cut it, for the Messenger of Allah ﷺ used to stretch it out and hold it. (Using translation from Abū Dāʾūd 4196)
«كَانَتْ لِي ذُؤَابَةٌ وَكَانَ رَسُولُ اللهِ ﷺ يَمُدُّهَا وَيَأْخُذُ بِهَا»