Commento su Bega'im 3:2

נותנין לו שבעת ימי המשתה – as it is written (Leviticus 13:14): “But as soon as ]un-discolored flesh] appears in it”/"וביום הראות בו [בשר חי]" since the All-Merciful (i.e., God) writes "ובהראות"/”as it appears”, what is "וביום"/as soon as? To inform you that there is a day that you examine and there is a day that you don’t examine.

A bridegroom on whom a nega has appeared is given the seven days of the marriage feast [in which he is not examined]; [This grace period is given to] him, and to his house and to his clothing. A priest should not examine a bridegroom, or a bridegroom's house or clothing, for a nega for the entire period of the seven day marriage feast.

Similarly during a festival, one is granted exemption from inspection during all the days of the festival. Similarly, nobody should be examined during a festival. In both occasions we fear that the nega would be pronounced impure and the person would have to be sent away in the midst of his marriage feast, or a festival and he would not get to rejoice with the community. This mishnah is testimony to the great significance the rabbis lent to the joyous occasion of a wedding or a festival. These celebrations override the biblical concern for a nega, so much so that we can ignore the nega for a week. We can also see from here that the issue with negaim is not one of health, for if it were, then we could hardly imagine delaying its treatment for a week.