John Gill Commentary Leviticus 22:5

"or whosoever toucheth any creeping thing, whereby he may be made unclean, or a man of whom he may take uncleanness, whatsoever uncleanness he hath;" — Leviticus 22:5 (ASV)

Or whosoever touches any creeping thing, by which he may be
made unclean
Jarchi thinks this respects the measure or quantity of what is touched, as if but the quantity of a lentil or small pea, see (Leviticus 11:31–38); or a man of whom he may take uncleanness, whatsoever uncleanness he
has;
as of a leper, a profluvious, or a dead man; Jarchi interprets it of the latter, and of the quantity which defiles, which is that of an olive; who also observes, that the phrase, "whatsoever uncleanness", includes touching a profluvious man or woman, a menstruous woman, and a new mother.