Nor could they spend anything (for the cause) - small or great- nor cut across a valley,(1372) but the deed is inscribed to their credit: that Allah may requite their deed with the best (possible reward).
1372 Cut across a valley: this is specially mentioned in a symbolical way, as denoting an individual act of heroism, dash, or bravery. To march with the troops along valleys, or, spiritually, tread paths of danger along with our Comrades, is good and praiseworthy; but one that dashes across a stream, all alone, for some special deed of bravery where the elan of comradeship does not sustain him, needs special mention. Notice that both the things mentioned in this verse—the spending of resources and the dashing across a valley—are individual acts, while those mentioned in the last verse are collective acts, which are in some ways easier. The individual acts having been mentioned, the next verse follows naturally.