This can be stated in active form. Alternate translation: "the number of days that God required" (See: [[rc://en/ta/man/translate/figs-activepassive]])
"for them to become ceremonially clean." You can also state God's role. Alternate translation: "for God to consider them to be clean again" (See: [[rc://en/ta/man/translate/figs-explicit]])
"to bring him to the Lord" or "to bring him into the Lord's presence." This was a ceremony acknowledging God's claim on the firstborn children who were male.