To place oneself under greater restrictions/ be self-demanding
He took extra care or severity in his conduct.
("A man shall fill his bride's bosom with wheat for seed, but not for eating, which was Rabban Gamaliel's bosom...and not because she went that way, but because she wanted to make it worse for herself" - Baba Matzi'a 5:8, and so: "It was worse for himself! He was very afraid and very anxious, for what was to come, a calamity, an hour of ease" - Bialik/ Yom The short sixth, a kang, and a kane: "Even if he is a winemaker, he is a leaven on himself, even if it is a burnt wine that has no yeast on it, he does not drink like others" - Agnon/ City and its Fullness, 328)
Translation
Expression (Hebrew)
הֶחְמִיר עַל עַצְמוֹ
Definition (Hebrew)
נָקַט בְּהַקְפָּדָה יְתֵרָה אוֹ בְּחֻמְרָה לְגַבֵּי אֹפֶן הִתְנַהֲגוּתוֹ שֶׁלּוֹ.
("מַלְוֶה אָדָם אֶת אֲרִיסָיו חִטִּין בְּחִטִּין לְזֶרַע אֲבָל לֹא לֶאֱכוֹל שֶׁהָיָה רַבָּן גַּמְלִיאֵל מַלְוֶה אֶת אֲרִיסָיו חִטִּין...וְלֹא מִפְּנֵי שֶׁהֲלָכָה כֵּן אֶלָּא שֶׁרָצָה לְהַחְמִיר עַל עַצְמוֹ"- בָּבָא מְצִיעָא ה ח, וְכֵן:"מַחֲמִיר הָיָה עַל עַצְמוֹ! יָרֵא וְחָרֵד הוּא מְאֹד מְאֹד, שֶׁמָּא יְאַחֵר, חָלִילָה, שָׁעָה קַלָּה"-בְּיָאלִיק/ יוֹם הַשִּׁשִּׁי הַקָּצָר, א קנג, וְכֵן:"עַד הֵיכָן הוּא מַחֲמִיר עַל עַצְמוֹ,אֲפִלּוּ יַיִן שָׂרוּף שֶׁאֵין עָלָיו חֲשָׁשׁ אֵינוֹ שׁוֹתֶה מִשֶּׁל אֲחֵרִים"- עַגְנוֹן/ עִיר וּמְלוֹאָהּ, 328)