2/261-262 — Seven ears of grain
"The case of those who spend their wealth in God's way is like a grain that grows seven ears; in every ear a hundred grains."
The comparison is chosen from agriculture and a number is given: one grain → seven ears → a hundred grains in each ear.
The function of the number is worth recording: the verse could have contented itself with saying "He multiplies"; and indeed at the end of the sentence it says this too, with wa'llāhu yuḍāʿifu li-man yashāʾ. But it gives the number first. A concrete reckoning is set before an abstract promise.
And the field the comparison chooses is the field in which a person does not see the result of his labour. As was treated at al-Wāqiʿa 56/63-64: it is the human being who sows, not he who makes it grow. Spending is set in the same place.
ثُمَّ لَا يُتْبِعُونَ مَآ أَنفَقُوا۟ مَنًّا وَلَآ أَذًى — "then they do not follow what they have given with reproach and hurt."
مَنّ — root م-ن-ن: to cut; and to enumerate one's kindnesses. The lexicographers make the connection thus: reproach cuts the bond of what has been given.
The condition is placed not on the act of giving but on what comes after: thumma lā yutbiʿūn — "then they do not follow it with…". Spending, that is, does not end at the moment of giving.