In the parsha of tzitzis: וְהָיָה לָכֶם, לְצִיצִת, וּרְאִיתֶם אֹתוֹ וּזְכַרְתֶּם אֶת-כָּל-מִצְוֹת ה’, וַעֲשִׂיתֶם אֹתָם; וְלֹא-תָתוּרוּ אַחֲרֵי לְבַבְכֶם, וְאַחֲרֵי עֵינֵיכֶם – You will wear these tzitzis. When you see them, you will be reminded of all God’s commands, and you’ll do them – and you won’t stray after your hearts and eyes. (15:39)
Beyond the obvious implication of not dwelling on inappropriate sights, the Sfas Emes teaches that this ties in to the beginning of the parsha, with the spies. This charges us to not to be led astray by appearances, one of many of that generations mistakes וְלֹא -תָתוּרוּ אַחֲרֵי לְבַבְכֶם, וְאַחֲרֵי עֵינֵיכֶם – our eyes and hearts literally “scout” for us, and we are not to be led astray.
What if their worst fears had been confirmed, and they indeed faced a land inhabited by hordes of strong, ruthless, well armed, well trained men? Would Hashems assurances have meant less than if they had no knowledge of the matter?
The Sfas Emes points out how taking things as they appear is a character flaw that is caused by a deficiency in faith and trust. If they had truly believed and trusted Hashem, this episode could not have taken place. This why the very next verse לְמַעַן תִּזְכְּרוּ, וַעֲשִׂיתֶם אֶת-כָּל-מִצְוֹתָי – not “remind yourself” so much as “never forget” – by internalisation. Never lose sight of the bigger picture.