Vayikra 15:13

וכי יטהר means WHEN HE CEASETH [FROM HIS ISSUE] (Sifra, Metzora Parashat Zavim, Chapter 5 1). שבעת ימים לטהרתו [THEN SHALL HE NUMBER TO HIMSELF] SEVEN DAYS FROM THE DATE WHEN HE CEASED — i. e. seven days clean (free) from the uncleanness resulting from the issue, i. e. in which he sees no issue, and all of them (of the seven days) must be consecutive (Sifra, Metzora Parashat Zavim, Chapter 5 6).

וְכִֽי־יִטְהַ֤ר הַזָּב֙ מִזּוֹב֔וֹ וְסָ֨פַר ל֜וֹ שִׁבְעַ֥ת יָמִ֛ים לְטׇהֳרָת֖וֹ וְכִבֶּ֣ס בְּגָדָ֑יו וְרָחַ֧ץ בְּשָׂר֛וֹ בְּמַ֥יִם חַיִּ֖ים וְטָהֵֽר׃

And when he that has an issue is cleansed of his issue; then he shall number to himself seven days for his cleansing, and wash his clothes, and bathe his flesh in running water, and he shall be clean.