Yissochar, of the town of Barkai, wore gloves as he brought Korbanos, so as not to dirty his hands. This was wrong because it was a Chatzitzah and through this, he denigrated Hashem’s Korbanos.
Rav Yitzchok Zilberstein Shlit”a was asked if a Mohel can wear gloves when performing a Bris Mila?
See, in our Gemorah, it seems to say that to wear gloves so as not to touch a Mitzvah, is denigrating the Mitzva.
He answered, that a Mohel who wears gloves by a Bris so as not to infect the baby, is permitted to do so because he does not thereby denigrate the Mitzvah.
Yissochar of Barkai, wore gloves for his own honor so as not to dirty himself. In effect, he was stating that his own honor was dearer to him than the Mitzvah, thereby denigrating the Mitzvah.