וְאִם־בַּהֶרֶת֩ לְבָנָ֨ה הִ֜וא בְּע֣וֹר בְּשָׂר֗וֹ וְעָמֹק֙ אֵין־מַרְאֶ֣הָ מִן־הָע֔וֹר וּשְׂעָרָ֖ה לֹא־הָפַ֣ךְ לָבָ֑ן וְהִסְגִּ֧יר הַכֹּהֵ֛ן אֶת־הַנֶּ֖גַע שִׁבְעַ֥ת יָמִֽים׃
And if the bright spot be white in the skin of his flesh, and the appearance thereof be not deeper than the skin, and the hair thereof be not turned white, then the priest shall shut up him that hath the plague seven days.
Rashi on Leviticus
ועמק אין מראה AND ITS APPEARANCE BE NOT DEEPER [THAN THE SKIN] — I do not know the meaning of this.
Sforno on Leviticus
ועמוק אין מראה מן העור, even though the sages (Shevuot 6) have said that everything which looks white is described a looking deep, recessed, as the sun appears as if deeper than the shadow, so that the wording of our verse appears to be incompatible with the statement of the sages, seeing that the skin itself is a form of something whitish the Torah means that the relationship of the normal skin to the whiteness of the tzoraat is comparable to the appearance of the shadow to the sun. [a spot of shadow on a bright day, is after all not “black” as is the darkness of the night. In fact, compared to the darkness of the night, it might be viewed as a weak “white.” Ed.]
Rashbam on Leviticus
ועמוק אין מראה, it is not the same kind of white as the other kinds of scales on the skin mentioned thus far.