Many Chassidim had the Minhag of preparing their water supply for the entire Pesach before the Yom Tov. This way, they wouldn’t have to be concerned about which utensils were used by other, including גוים, to obtain the water from the well.
R’ Hillel of Paritch, who was extremely scruples also kept this minhag. One Pesach, to his great distress, he opened one of the water bottles and discovered a kernel of wheat floating on the top.
Such an event would have upset any Jew; how much more so did it affect R’ Hillel. Indeed, he was very distraught. “How did this happen,” he asked himself. “What did I do or not do that that caused this to happen to me?”
After deep, thorough introspection, Reb Hillel came to the following conclusion: “When I come to Lubavitch, I try as much as possible to avoid being seen by the Rebbe. The Rebbe does not have to see my coarseness. If only I would have allowed the Rebbe to see me, his gaze would have protected me from such an sin.
(‘ר’ הלל’ מפי ר’ שמואל לעוויטן)