聿 writing brush

聿, cognate of 筆(笔), originally a writing brush. In oracle bone script and bronze script, 聿 was like a hand hold a writing brush. It serves as phonetic as well as semantic component to form characters. 

筆 was created later to replace 聿 to mean a writing brush. ⺮ indicates that the writing brush is made of bamboo.  The simplified form 笔 depicts a brush made of bamboo ⺮ and fine animal hair 毛.

Characters formed by the phonetic component 聿

侓垏峍律津珒肂硉貄銉茟 lù lǜ lù lǜ jīn jīn sì lù sì yù yù

Characters formed by the semantic component 聿

When serves as semantic component, it expresses something related to a pen or writing.

笔划	汉字	拼音	笔划	汉字	拼音
6	聿	yù	8	肃	sù
10	肂	sì	10	肁	zhào
13	肆	sì	13	肄	yì
13	肅	sù	14	肇	zhào
14	肈	zhào	8	建	jiàn