(1 syl.). To strain courtesy. To stand upon ceremony. Here, strain is to stretch, as parchment is strained on a drum-head. When strain means to filter, the idea is pressing or squeezing through a canvas or woollen bag.
Strain at a gnat and swallow a camel.
To make much fuss about little pecadillos, but commit offences of real magnitude. “Strain at” is strain out
). The allusion is to the practice of filtering wine for fear of swallowing an insect, which was “unclean.” Tyndale has “strain out” in his version. Our expression “strain at” is a corruption of strain-ut,
“ut” being the Saxon form of out, retained in the words ut-most, utter, uttermost,
The quality of mercy is not strained
(Merchant of Venice,
iv. 1)- constrained or forced, but cometh down freely as the rain, which is God's gift.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894