Merciless
In Chinese, the Pinyin is w ú Q í n à sh à OMI à n, which means no affection. The source is the supplement to the journey to the West.
The origin of Idioms
The second chapter of the supplement to the journey to the West: "I've seen him several times, and I'm not a person who has no feelings for others."
Idiom usage
As a predicate, attribute, etc
Merciless
be overwhelmed by an unexpected favour - shòu chǒng ruò jīng
take pity on the poor and the old - lián pín xù lǎo
the defects do not obscure the virtue - yú bù yǎn xiá
violate rules and overstep all bounds - dàng jiǎn yú xián
houses have adequate supplies and people live in contentment - jiā jǐ mín zú
serve parents while living and give proper burial after death - yǎng shēng sòng sǐ