Surah 33. Al-Ahzab, Ayah 19

In times of danger, they would look to the holy Prophet for protection, and keep themselves snugly from the fight. When the danger is past, they will come and brag and wrangle and show their covetousness or greed for gain though they gave of themselves but sparingly.

Ashihhatan: covetous, grasping, niggardly. Here the meaning is twofold: (1) they spare themselves in the fight as compared with you; they are niggardly with themselves as against you: they contribute little either in personal effort or with their money and resources; and (2) they covet any gains made or booty won, on the part of the real fighters.

Even any good they may have done becomes vain because of their motives of envy, greed, and covetousness, and their cowardice.

It is not surprising that men's deeds fall as it were dead because there is no pure motive behind them. For men it may be difficult to probe motives, but it is easy for Allah, Whom hypocrisy or false show can never deceive.