Little Things Count

The Shabbos before an orphan bride's wedding, a rebbetzin who runs a tzedakah fund has paid for everything. Her husband asks one more question, and her answer catches him off guard.It connects to the two midwives in Parshas Shemos. Rashi says Shifra is Yocheved and Puah is Miriam, named for how they tended the newborns. They defied Pharaoh and kept the babies alive. So why does the Torah name them for the gentle details, and why does Rav Pinkus say that is what earned them such lasting reward?