Musar sur L’Exode 3:8

First of all let me explain that there is a difference between the meaning of the word טוב when it is spelled with the vowel חולם and when it is spelled with the vowel שורוק. The former spelling is employed when the visible "good" i.e. the נגלה, only is revealed. When the word is spelled with the vowel שורוק, however, the good that is meant is also the intrinsic good, that which is not visible. We observe this principle when checking the spellings of these three "gifts." When referring to Torah, Psalms 119,72, we have טוב לי תורת פיך מאלפי זהב וכסף, "The Torah of Your mouth I prefer to thousands of pieces of gold and silver." The word טוב in this case is spelled with the vowel חולם. On the other hand, six verses earlier in Psalms 119,66, we find טוב טעם ודעת למדני, "teach me good sense and knowledge," and the word טוב is spelled with the vowel שורוק. Similarly we find ארץ ישראל described as ארץ טובה, with the vowel חולם, on occasion (Exodus 3,8), whereas in Isaiah 1,19, we read "אם תאבו ושמעתם, טוב הארץ תאכלו," "if you agree and listen, you will eat of the good of the land." In this case the word טוב is again spelled with the vowel שורוק. Concerning this verse our sages have said that Isaiah speaks of "the world which is totally good," since they could not understand what other justification there could be for the different spellings. They concluded that in that distant future there will no longer be a difference between the hidden aspects of טוב, and the part which is visible to all. At that time, a blessing will no longer contain also those elements that are not good. A reference to something intrinsic is appropriate only if the same gift described contains both external and internal features. This is why they described that future as one that is כלו טוב, i.e. "totally good."