(5) Now thus said the CREATOR of Hosts: Set your minds-and-hearts upon your path!
In English, the heart is the seat of emotion, while in Biblical Hebrew, the kidneys are often considered the seat of emotion. " Heart - לב/לבב - is somewhere between what we call "mind" and what we metaphorically call "heart." Thus my translation, "heart-and-mind." In Modern Hebrew, "to set one's heart - לשים לב" means "to pay attention."
כֹּ֥ה אָמַ֖ר יְהֹוָ֣ה צְבָא֑וֹת שִׂ֥ימוּ לְבַבְכֶ֖ם עַל־דַּרְכֵיכֶֽם׃
Thus said the CREATOR of Hosts: Set your minds-and-hearts upon your path!
Haggai really wants us to pay attention! In my Mussar practice, I often use this phrase from Hagai - "simu l'vavhem al darheihem - set your minds-and-hearts upon your path" - as a reminder phrase for the middah of Zehirut: being careful about one's deeds, watchfulness, what Alan Morinis calls "shining awareness."
And here it says a second time, "Thus said the CREATOR of Hosts: Set your minds-and-hearts upon your path!" For at the beginning of this prophecy, "It commanded them "Set you minds-and-hearts upon your path" that they should contemplate the curse clinging to all the work of their hands. And after having said this to them It commanded them to set their minds and hearts on their path that they should repair them. Namely, that when they ascend the mount and bring wood and build the Temple, It advises the that even though the Temple might be small and without wealth, Hashem will be pleased with it and will be honored there. For honor does not always depend on wealth, but on the pleasing intention of the good and true worshiper.
Abarbanel's comment can be generalized as telling us that the two repetitions of Hagai's call to pay attention speak to two stages of Zehirut: First, consideration of what have your deeds been and how have they worked out. Second, consideration of what we might do next to improve the situation, if it needs improvement.
And finally, our repaired deeds don't have to be grand or flashy or expensive! Honor comes from the pleasing intention of the good and true worshiper.
(ח) ואולם הנה זאת באמת אחת מתחבולות היצר הרע וערמתו להכביד עבודתו בתמידות על לבות בני האדם עד שלא ישאר להם ריוח להתבונן ולהסתכל באיזה דרך הם הולכים.
(ט) כי יודע הוא שאלולי היו שמים לבם כמעט קט על דרכיהם, ודאי שמיד היו מתחילים להנחם ממעשיהם, והיתה החרטה הולכת ומתגברת בהם עד שהיו עוזבים החטא לגמרי.
(י) והרי זו מעין עצת פרעה הרשע שאמר (שמות ה): תכבד העבודה על האנשים וגו', שהיה מתכוין שלא להניח להם ריוח כלל לבלתי יתנו לב או ישימו עצה נגדו, אלא היה משתדל להפריע לבם מכל התבוננות בכח התמדת העבודה הבלתי מפסקת.
(יא) כן היא עצת היצר הרע ממש על בני האדם, כי איש מלחמה הוא ומלמד בערמימות, ואי אפשר למלט ממנו אלא בחכמה רבה והשקפה גדולה. הוא מה שהנביא צווח ואומר (חגי א׳:ה׳): שימו לבבכם על דרכיכם.
(8) In truth, this is one of the cunning strategies of the evil inclination, to relentlessly burden people's hearts with his service so as to leave them no room to reflect and consider which road they are taking.
(9) For he knows that if they were to put their ways to heart even the slightest bit, certainly they would immediately begin to feel regret for their deeds. The remorse would go and intensify within them until they would abandon the sin completely.
(10) This is similar to the wicked Pharaoh's advice saying "intensify the men's labor..." (Ex. 5:9). His intention was to leave them no time whatsoever to oppose him or plot against him. He strove to confound their hearts of all reflection by means of the constant, incessant labor.
(11) This is precisely the ploy employed by the evil inclination on human beings. For he is a skilled warrior, expert in the art of cunning. It is impossible to escape from him without great wisdom and far-reaching vision. This is what the prophet screamed out "give heed to your ways!" (Chagai 1:7).
(15) And now set your minds-and-hearts, from this day forward: Before any stone has been set upon stone in the Temple of the Eternal,
(18) Take note, from this day forward—from the twenty-fourth day of the ninth month, from the day when the foundation was laid for the Eternal’s Temple—take note
"And now, set your minds-and-hearts." In addition to wanting them to pay attention and consider God's behavior towards them, so that from this day, on which they begin to build the Temple, forward, It's behavior might change to blessing and benefit, it hints also that they should set their minds-and-hearts on the Eternal's sanctuary, that they strive to have their hearts found in the Eternal's sanctuary, meaning that the building and the work of the Temple not be only a bodily activity, but the action of the heart and the soul. And before you set stone upon stone to found the building, set your hearts in GOD's Temple. For a building of stone, without the heart, will contain no holiness, for holiness clings not to external actions which apply to external things, as was written above.