Surah 42. Ash-Shura, Ayah 20

I.e., whereas those who live righteously and turn their endeavours towards spiritual ends are sure to receive in the hereafter more than they are hoping for, those who strive exclusively after worldly rewards may - but not necessarily will - achieve something, and not necessarily all, of their aims, without having any reason to expect "a share in the blessings" that await the righteous in the hereafter.

The parable is from the efforts of the husbandman, who ploughs and prepares the soil, sows the seed, weeds in due season, and reaps the harvest, You reap as you sow. But Allah will add manifold advantages for spiritual tilth. To those who are only engrossed in the vanities of this world, something may accrue in this world, but the next world is closed to them.