After planting his seed, he focuses on the harvest and has faith that the seed he planted will provide him with a bountiful crop.
Thoughts are the seeds we sow and once we plant our seed (what we want), we must have faith in it to grow and manifest itself into our physical reality.
If you plant a seed of "I want this" and then have doubts, it is like the farmer having doubts about the crop he wants and ripping his seed out of the soil and planting a new one, never allowing the crop he originally planted to grow into fruition.
You only have to want what you want, once. That is sufficient for your want to bear fruit. After you are clear about what you want, nurture your want by seeing it in your mind's eye until it becomes real to you. Once it becomes real in your mind's eye, shortly thereafter it will show up in your physical reality...
Expect what you want to become
your Reality and it will, just don't
expect it to come to you in a certain way.