548. Letting Blood, Measuring Grain

Brachos 10:21

(People used to let blood for medicinal purposes.) One who goes to let blood should say, “May it be Your will, Hashem our God, that this activity heal me because You are a generous Healer.” After letting blood, one should recite the bracha that God heals the sick (Rofei cholim).

Brachos 10:22

One who goes to measure his grain should say, “May it be Your will, Hashem our God, to send blessing to the work of my hands.” When he starts to measure, he should say, “Blessed be the One Who sends blessings to this pile of grain.” If one asks God for mercy after he has already measured his grain, it is considered a prayer uttered in vain. Whenever one prays to God about things that have already occurred, it is considered a prayer uttered in vain.