Some hold to the principle that when we perform good deeds we should have no motivation or ulterior motive. Others believe that when we perform good deeds, we should expect a return of a thousand fold. If the seeds are healthy, the earth always returns at least a thousand fold.
It is a basic principle of sowing and reaping that if we plant one healthy grain of corn, we will have a corn tree that bears at least a dozen ears of corn. If we continue to plant, eventually we can have an entire acre of corn, or more, from that single seed. Similarly, one pear seed can produce a tree that will bear fruit for decades.
So what should be our mindset when we do good deeds? Should we always expect a thousand-fold return? It depends on the motivation. If the motivation is self interest, fear or greed, the good deed can be as corrupted as a rotted grain of corn--it can produce no harvest and will offer no reward. On the contrary, if the motivation is love, gratitude, or compassion we should expect a healthy yield.
When the Scriptures challenge us to act only within the parameters of love, gratitude or compassion, it is not because God is seeking to control our actions. It is because he knows that we gain nothing and will reap no harvest unless the motivation is clean, healthy, and powered by love.