In this week's Parsha, Avraham is forced to go down to Egypt with Sarah due to a famine in Canaan. Avraham asks Sarah to act incognito as his sister while in Egypt saying, "so that it will be good for me and save my life."(בראשית י"ב:י"ג) The Midrash says that we learn from here that one is allowed to slaughter an animal on Shabbos in order to save a sick person's life. This Midrash forces the Ksav Sofer to ask why we couldn't learn this law from the Posuk that says, "And you shall live by them",(ויקרא י"ח:ה`) where we learn in general that one is allowed to commit a sin in order to save a life. He explains that from that Posuk one can learn only that one can sin to save his own life. We still would not know, however, that one can sin to save some one else's life. We therefore see from the fact that Sarah was allowed to do something inappropriate in order to save Avraham's life that one can in fact sin to save some one else's life. We can therefore learn from here that one can violate Shabbos to save a sick person's life.
The Tiferes Shmuel, based on Rashi here, also has a question on this Posuk. Rashi says that by saying the words "so that it will be good for me," Avraham showed that he expected to receive gifts. Then the Posuk also adds his life would be saved. However, how could Avraham mention gifts prior to life when it would seem that all the money and gifts in the world would fall secondary to life itself? Furthermore, it is written "ושונא מתנות יחיה", "the one who hates gifts will live" (משלי ט"ו:כ"ז). How then could Avraham even be thinking of getting gifts, which the Posuk implies shortens life, at a moment when he should be thinking only of how to live. The תפארת שמואל answers that Avraham was actually trying to think of an action which would ensure him his life and he came across this idea that the one who stays away from gifts will live. He therefore decided to say that Sarah was his sister and he consequently would be given gifts (when Pharoh would take her for a wife). Avraham would then refuse to accept the gifts showing that he wishes to avoid them, knowing that the one who hates gifts will live. We thus see that Avraham had to expect gifts in order to live.
The Tiferes Yisrael is also troubled as to why Avraham was thinking of gifts at a time when Sarah and he were in such great danger. He explains that when the famine began, Avraham opened up his store-houses and fed every one that was hungry until he had no food left. Then he took Sarah and all his people and went to Egypt. On his way down, Avraham managed to buy food for his people on credit, but when he got to Egypt he didn't know how he would supply his people with food. At the same time, he had to worry about how to save his wife from Pharoh. He therefore told Sarah to act as his sister and then they would give him gifts. Then Avraham would use the gifts to buy his people food and he hoped that in the merit of this tremendous Mitzvah of Tzedakah and Gemilas Chasadim toward his people, Sarah would be protected from sleeping with Pharoh.
From the Tiferes Yisrael's explanation of why gifts preceded life in Avraham's statement, we learn the extreme importance of giving Tzedakah and doing Gemilas Chasadim. Avraham and Sarah were saved in the merit of these Mitzvos. The Gemara in Bava Basra (דף ה`) adds that Tzedakah also hastens the Geulah. We should therefore learn from Avraham's example the value of trying our utmost to give Tzedakah and do Chessed. Hopefully this will protect our lives and bring the Mashiach speedily in our days.