לא יחל דברו ככל היוצא מפיו יעשה
The word of a Jew is sacred. He must stand behind his word. When a person does not keep his word, he is mechallel diburo, desecrates his word. Chillul is a strong term. We use the term chillul with regard to desecrating Hashem’s Name – chillul Hashem. Also, when a bas Kohen, daughter of a Kohen, acts in a morally profligate manner, the Torah writes, Es avihah hee mechalleles, “She desecrates her father” (Vayikra 21:9). Apparently, the sanctity of a Kohen, the sacredness of a person’s word, are of a similar nature to the sanctity of Hashem, in the sense…