en_tn/num/30/05.md

her vow and her promise

These two phrases have very similar meanings. They emphasize what she has promised to do. AT: "her vow" (See: rc://en/ta/man/translate/figs-doublet)

she took on herself

Here the woman committing herself to fulfilling her vows is spoken of as if her vows were a garment that she placed on herself. AT: "that she committed herself to" or "that she made" (See: rc://en/ta/man/translate/figs-metaphor)

will remain in force

This is an idiom. It means that her vows will remain in effect and she will be required to fulfill them. See how you translated this phrase in Numbers 30:4. AT: "she will be obligated to fulfill" (See: rc://en/ta/man/translate/figs-idiom)