出典:Wiktionary
An allusion to the Biblical tale (Matthew 9:20) of the woman who was cured of disease when she touched the hem of Christ's garment.
touch the hem of someone's garment (三人称単数 現在形 touches the hem of someone's garment, 現在分詞 touching the hem of someone's garment, 過去形および過去分詞形 touched the hem of someone's garment)