origin of 気にくわない/use of 食う

Question

Does anybody know where the くわない　comes from?

あいつの態度が気にくわない |i don't like his attitude

My dictionary tells me the expression means:

不満である。気にいらない。and the kanji is 食う but I wonder does anyone understand the etymology?

Answer 1

There are several theories (or guesses, rather) on this page:

1. 食わない is used in the sense of 噛み合わない, where 噛み合わせ means engaging or meshing of gears or occlusion. Thus a more metaphorical use of 気が合わない.

2. 食わない is used in the sense of 口に入る (or 口にくわえる; see def. 10 of 大辞林). Another metaphorical use.

3. 食う replaced 召す in the phrase 気に召す, because 召す was once close in meaning to 食べる/食う (cf. 召し上がる).