Charles Ellicott Commentary Leviticus 15:25

"And if a woman have an issue of her blood many days not in the time of her impurity, or if she have an issue beyond the time of her impurity; all the days of the issue of her uncleanness she shall be as in the days of her impurity: she is unclean." — Leviticus 15:25 (ASV)

Have an issue ... many days. —The last case is that of a chronic issue, arising from a physical disorder. This is the kind of complaint from which the woman suffered who came to Christ (Matthew 9:20; Luke 8:44). As long as she suffered from it, which sometimes lasted for many years, she rendered things unclean and was herself ritually unclean, in the same way as in her menses.