came at his expense
Caused him to lose. The profit of one was gained at the loss of another.
(Modern Hebrew)
Translation
Expression (Hebrew)
בָּא עַל חֶשְׁבּוֹנוֹ
Definition (Hebrew)
גְּרָם לוֹ להפסיד. רֶוַח שֶׁל אַחֵר גַּבָּהּ מִמֶּנּוּ הפסד.
(הָעִבְרִית הַחֲדָשָׁה)