In Parshas Toldos (26:12), we are taught that “Yitzchok planted in that land and he found that year, hundred times and Hashem blessed him.”
Why does it say that land and that year? That land was arid, not suitable for planting – and that year was an especially hard agricultural year. But with all that going against him, Yitzchok planted and Hashem made his crops grow 100 times the amount it should have grown.
Okay, a message of hope, even in our hard economy time. Plant, and, so long as we are doing the right things and focused on G-d, G-d can bless us even in this terrible economy.
The Parsha then goes on and relates the issue of wells, of how Yitzchok would dig them and his enemies would stop them up. Here too, he doesn’t despair, but each time begins digging anew, uncovering the stopped up wells.
The Chofetz Chaim teaches us that the digging of wells teaches us the importance of perseverance, of not giving up. Yitzchok dug, got it taken away, moved on and dug again. So too, if you aren’t having success in learning, don’t give up, keep trying. The same works in business and in anything. And most especially it works in spirituality. Nu, so things got cloudy and you messed up. Get your handy shovel out and start digging. Uncover your wells of clarity.
 Rashi and other meforshim: why do we care the amount of times it grew? Because of the calculations of Ma’aser (tithing). The Avos did the Mitzva of Ma’aser and therefore there had to be calculations of what they reaped. Seforno then point out that after it talks about the amount that had to be ma’asered (meah shearim), then the verse says Hashem blessed him – because giving Ma’aser brings the blessings of wealth.
To read more about the laws of Maaser, you can go to this site: http://www.torah.org/advanced/weekly-halacha/5763/mishpatim.html