1.   Shabbos is associated with the natural order of creation and time. Rosh Chodesh is novel and supra-natural, being set by the ruling of the Sanhedrin. By combining the two we unite nature and novelty and influence our Divine service. This theme is optimized on Shabbos Vaeira, Rosh Chodesh Shvat. The month of Shvat is connected with the tribes of Yosef and Asher. Vaeiraincludes the aspect of “seeing.” The regular must become new and the new must be continuous.

2.   Why did each plague last one week and why three weeks for warnings? After each calamity the Egyptians were given time to contemplate, and there was movement on their part. In addition to punishing the Egyptians, the plagues educated the Jewish people. If you don’t see immediate success when you reach out, don’t give up. Be persistent and you will succeed.