סוּס שֶׁקִּיבַּלְתָּ בְּמַתָּנָה אַל תִּבְדֹּוק אֶת שִׁינָּיו

ביטוי (אנגלית)

Never look a gift horse in the mouth

הגדרה (אנגלית)

Figuratively: one should not be critical of something received without effort. Or: one cannot expect perfection from something that came without effort.

(Modern Hebrew)