שׁ֣וֹר אוֹ־כֶ֤שֶׂב אוֹ־עֵז֙ כִּ֣י יִוָּלֵ֔ד וְהָיָ֛ה שִׁבְעַ֥ת יָמִ֖ים תַּ֣חַת אִמּ֑וֹ וּמִיּ֤וֹם הַשְּׁמִינִי֙ וָהָ֔לְאָה יֵרָצֶ֕ה לְקָרְבַּ֥ן אִשֶּׁ֖ה לַיהוָֽה׃
Ein Stier oder ein Schaf oder eine Ziege bleibe sieben Tage nach der Geburt bei seiner Mutter, und erst vom achten Tage an wird es gnädig aufgenommen als Feueropfer für den Herrn.
Zohar
And many thousands and myriads [of spirits] come out at one time to the world. And from the day that they come out, they are not called souls, until they settle themselves into a body. And how long [does this take]? 33 days. This is why it is written "thirty days and three days etc" (Lev. 12:4). "And she will be impure for seven days" (Lev. 12:2) - behold, for all seven days the spirits do not go up to her, to connect themselves on her, and all those seven days the spirit goes into the body, to find its place. And accordingly it is written "and he will be under hi mother for seven days" (Lev. 22:27).