en_tn_condensed/act/21/24.md

Take these men and purify yourself with them

They had to make themselves ritually pure so they could worship in the temple.

pay their expenses for them

"pay for what they will need." The expenses would go toward buying a male and female lamb, a ram, and grain and drink offerings.

they may shave their heads

This was a sign that the person had completed what they promised God they would do.

the things they have been told about you

"the things that people are saying about you"