Musar su Esodo 12:17

ושמרת את המצות. Rashi (12,17) comments on this verse: "Be careful with the מצות so that they will not become leavened. We learn from this verse that when the dough begins to swell you have to put cold water on it. Rabbi Yoshiah understands the word מצות here as having a different meaning. It can be read as Mitzvot, commandments. The message we can derive is that just as one must not allow the dough to become leavened through leaving it unattended for any length of time, so one must not tarry before carrying out a מצוה when the opportunity presents itself.

Therefore, the sages of blessed memory exhorted us: "And you shall watch over the Matzot" - if a Mitzva comes to your hand, do not delay its performance (lit. allow it to become Chametz)' (Mechilta Shemot 12:17).

Rabbi Judah, the son of Tema, said, "Be bold as a leopard, light as an eagle, fast as a deer, mighty as a lion to do the will of your Father in heaven" (Aboth 5:24). See how they warned that one make himself light and strong in order to fulfill the commandments! Thus did David say, "I made haste, and delayed not, to observe Thy commandments" (Ps. 119:60). Thus did our Rabbis expound : " 'And ye shall observe the matzot (Ex. 12:17), do not read it as matzot (unleavened bread), but read it is as mitzvot (commandments)" — meaning if an opportunity comes to you to do a good deed, do not let it grow stale but do it at once (Mekhilta de Rabbi Ishmael, vol. I., p. 74). It is very necessary to be agile and alert and strong in order to strive against the wicked — to be mighty of heart as Moses, our teacher, when he said, "Put every man his sword upon his thigh" (Ex. 32:27). And to be like Phinehas of whom it is said, "And when Phinehas, the son of Eleazar the son of Aaron the priest, saw it, he rose up from the midst of the congregation and took a spear into hand" (Num. 25:7). Therefore, take care to be quick to separate yourself from the company of the wicked, so that you will not be part of their designs and their plans. Above all it requires zeal to do repentence. One must hurry and he should not delay to follow the paths of repentence, and let him not be wicked for even one hour before God, may He be Blessed. See how alert the servants and ministers of kings are in the performance of their duties. All the more so must we be careful to be alert in our service to the King of Kings, the Holy One, Blessed be He.