Leviticus 13:5

And the priest shall look on him the seventh day: and, behold, if the plague in his sight be at a stay, and the plague spread not in the skin; then the priest shall shut him up seven days more:

Cross-reference

Leviticus 13:26 also orders a seven-day isolation for a burn — paralleling the initial isolation step begun in this verse.

Leviticus 14:8 describes a seven-day post-cleansing separation — a later stage in the leprosy process, parallel to the quarantine here.