וַיְהִ֣י אֲנָשִׁ֗ים אֲשֶׁ֨ר הָי֤וּ טְמֵאִים֙ לְנֶ֣פֶשׁ אָדָ֔ם וְלֹא־יָכְל֥וּ לַעֲשֹׂת־הַפֶּ֖סַח בַּיּ֣וֹם הַה֑וּא וַֽיִּקְרְב֞וּ לִפְנֵ֥י מֹשֶׁ֛ה וְלִפְנֵ֥י אַהֲרֹ֖ן בַּיּ֥וֹם הַהֽוּא׃
But there were certain men, who were unclean by the dead body of a man, so that they could not keep the passover on that day; and they came before Moses and before Aaron on that day.
Read Kabbalistic (mystical) interpretations of Numbers 9:6: Zohar and classical Jewish mystical sources, free online.