Musar su Malachia 3:10

“Do not try the Lord your God” (Deuteronomy 6:16). And we are warned with this that a man should not say, “I will make a trial with my service of charity [whether] the Lord will make my way successful; and I will test through the properness of my actions, whether my gold and silver will grow.” But the good man will not slacken from his toil in wisdom, knowledge and proper action when his path in the matter of his money and the rest of the goods of the body are not successful. And our Rabbis, may their memory be blessed, said (Taanit 9a) that only with tithes of the storehouse is testing [God] permitted, as it is stated (Malachi 3:10) “Bring the full tithe into the storehouse, and let there be food in My House, and thus put Me to the test.” King Solomon, peace be upon him, said (Proverbs 3:9-10), “Honor the Lord with your wealth, with the first of all your produce. And your barns will be filled with grain, [etc.].” Its explanation is, if you do not have like this - to be filled with grain when you give from your wealth and from the first of all your produce - but you are rather seized by days of poverty, “Do not reject the discipline of the Lord” (Proverbs 3:11), and know that this is also for your good. “For whom the Lord loves, He rebukes” (Proverbs 3:12), to do good for him in his end; that the reward in this world and his honor be exchanged for the good that is hidden and continues forever.

If you look closely you will find that what Rashi writes about "estimating," applies to all kinds of tithes, and not only to תרומה גדולה. Since Rashi writes that the estimate was based on how much the field was expected to yield, it appears that the method of estimating applied to all kinds of tithes, and not just to the מעשר ראשון. We may therefore conclude that already prior to the harvest Isaac "estimated" how much he would have to set aside as a tithe. Once the harvest was in the barn- at which time the obligation to give a tithe became operative, he measured carefully how much one tenth would amount to. Anything one eats from a crop before it is brought into the house or barn is not subject to tithes. Isaac, as we have shown, was especially careful to measure the grain even before anyone could have eaten from it. Since the verse under discussion deals with the commandment of tithing, it is appropriate for the Torah to add the words: "G–d blessed Him (Isaac)." We have a parallel verse in Malachi (3,10) when the prophet assures us הביאו את כל המעשר אל האוצר … והריקותי לכם ברכה עד בלי די, "Bring to Me all the tithes to the storage house,….and I will pour out for you endless blessings."

Rebeccah concluded that there was no point in living a life that was measured by the yardstick of the undiluted מדת הדין, seeing that hardly anyone could survive if he were to be measured by that attribute alone. This is why she said: קצ-תי בחיי, i.e. what good is my life under such circumstances! (Genesis 27,46) Unless some relief is found for the rest of the world's population this is the end of meaningful life. She referred to the tribe of חת, a Canaanite tribe whose daughters Esau had married. Seeing that the Canaanites were cursed already and that Esau himself was an outgrowth of the סטרא אחרא, she considered the combination as lethal, bound to lead to the oblivion of their offspring. Because of such considerations, the name that should by rights have been קצחי was changed to יצחק, to introduce the element of joy into their lives. The immediate cause for this was Isaac giving tithes which resulted in G–d blessing his efforts, as related in 26,12. It is strange that when Malachi 3,10 describes the blessing that results from tithing, he uses the expression of ארובות השמים, "the windows of heaven." Since the Torah uses the same expression at the onset of the deluge in Genesis 7,11, we wonder why the prophet would use an expression to symbolize blessing when that same expression had symbolized a curse on mankind in its prior usage in the Bible.