Don’t ask why the hand is wet, though.

濡れ手で粟（を掴み取る）
(Nurete de awa (wo tsukamitoru); “(grasping) millet with a wet hand”)

Definition:

Profit without hard work. Easy money. If you stick a wet hand into a container of fine grains such as millet seeds, the grains will stick to your hand without any further effort on your part; the image is of money accruing just as easily.

Breakdown:

The short form of the phrase comprises two noun, a verb, and a particle. The latter noun is 粟 (awa), common name “foxtail millet,” a cereal crop widely grown in east Asia for at least the past 2600 years. The former noun is 手 (te), “hand.” The hand is modified by the verb 濡れる (nureru), “to get wet,” in the prenominal use of its stem form, and marked by the particle で (de) as the means by which an action is carried out.

In order to discover what this action is, we have to look to the longer form of the phrase, which adds the object-marker particle を (wo) and a compound verb made from 掴む (tsukamu), “to grab,” in conjunctive form plus 取る (toru), “to take,” in sentence-final form. The wo marks the millet as the noun acted on by this compound verb, which logically enough can be translated as “to grasp,” “to get.”

Notes:

Some people replace 粟 with homophone 泡 (“bubbles,” “foam”). Based on this, some assume that the small size of the awa refers to something of little value, and take this saying to mean exactly the opposite – of making little profit no matter how hard one works. Naturally, both of these are errors, as is replacing the particle de with ni – a replacement that might make sense to someone who only knows the shorter form of the saying, but which should still be avoided.

Example sentence:

毎日宝くじを買っている人は濡れ手で粟を掴み取る夢を見ているかもしれないが、結局その夢もお金も泡のように消えて行く。

(Mainichi takarakuji wo katteiru hito wa nurete de awa wo tsukamitoru yume wo miteiru kamoshirenai ga, kekkyoku sono yume mo okane mo awa no you ni kiete yuku.)

[People who play the lottery every day are likely daydreaming of easy profit, but in the end they both vanish, the dream and their money alike.]