לרפואת א"מ ר' יצחק יונה בן חנה ור' מרדכי דוד בן קריינא בתוך שח"י
Rabbeinu Yonah [שערי תשובה ג' כ"ז] tells us a HUUUUGE chiddush of which this day, most people are not aware [even though all of Klal Yisrael read it yesterday in shul].
מן האזהרות התלויות בלב. השמר לך פן תשכח את ה' אלהיך (דברים ח׳:י״א) ואמרו רבותינו זכרונם לברכה כל מקום שנאמר השמר, פן, ואל, הרי זה לא תעשה. הוזהרנו בזה לזכור את הש"י בכל עת. וחייב האדם להשתדל לקנות לנפשו תמיד ההנהגות המחויבות מן הזכירה. כמו היראה והצניעות וקישוט המחשבות וטכסיס המדות. כי זרע הקודש ישיגו כל הנהגה נאוה והמעטירה בעליה מזכירת השם ית' כמו שנאמר - (ישעיהו מ״ה:כ״ה) בה' יצדקו ויתהללו כל זרע ישראל:
Among the [negative commandments] that are dependent on the heart are: “Take care lest you forget the Lord, your God” (Deuteronomy 8:11). And our Rabbis, may their memory be blessed, said (Sotah 5a), “Wherever it is stated in a verse, ‘beware,’ ‘lest’ or ‘not,’ this is [surely] a negative commandment.” We are warned [then] with this to remember God, may He be blessed, every instant. And a person is obligated to make efforts to always acquire for himself behaviors that are mandated by remembrance - such as fear, modesty, refinement of one’s thoughts and strategies [to acquire] good traits - so that the holy seed will attain every fine behavior and be crowned through it from the remembrance of God, may He be blessed, just as it is stated (Isaiah 45:25), “It is through the Lord that all the offspring of Israel Have vindication and glory.”
WOW!! A לאו דאורייתא not to forget Hashem. What does that entail? We have to have a sense of reverence as we stand before Hashem - יראה relates to ראיה, as if we see Him before us at all times. צניעות - We have to dress with modesty and act with modesty. Hashem is watching!! [Here then is a Torah source for dressing בצניעות]. קישוט המחשבות - Hashem is aware of every thought that goes through your mind!! Make sure they properly "adorn" you. And finally "טכסיס המדות" - acquire strategies to improve your middos. If you just say "I want to have good middos" w/o a plan - it won't work.
I saw one Gadol who asked: Why didn't Rabbeinu Yonah mention the greatest expression of not forgetting Hashem- keeping His mitzvos??!!!
He gives a deep answer כדרכו.
I think the simple answer is that the pasuk says in full הִשָּׁ֣מֶר לְךָ֔ פֶּן־תִּשְׁכַּ֖ח אֶת־יְהֹוָ֣ה אֱלֹהֶ֑יךָ לְבִלְתִּ֨י שְׁמֹ֤ר מִצְוֺתָיו֙ וּמִשְׁפָּטָ֣יו וְחֻקֹּתָ֔יו אֲשֶׁ֛ר אָנֹכִ֥י מְצַוְּךָ֖ הַיּֽוֹם. So the pasuk says explicitly that if one doesn't keep mitzvos he is forgetting Hashem. For that we don't need Rabbeinu Yonah.
