ב"ה, ט' ניסן, תשט"ז
ברוקלין.
שלום וברכה!
...ובודאי למותר לעוררו על הענין הידוע שלכל אחד ישנה מצוה שצ"ל זהיר טפי, והיא השער לעליית התפלות ובקשות שלו וגם כן השער להמשכת הברכה בהנחוץ לו לב"ב, ובנדון דידי' הוא ענין עבודת הקדש בישיבה מיסודה של כ"ק מו"ח אדמו"ר זצוקללה"ה נבג"מ זי"ע, וככל שיוסיף בזה יתוסף בכל הנ"ל לו ולב"ב בגשמיות וברוחניות.
בברכה לבשר טוב בכל האמור לעיל ולחג פסח כשר ושמח לו ולכל ב"ב שיחיו.
B"H, 9th of Nissan, 5716.
Brooklyn.
Shalom u'Vrachah!
...And it is certainly unnecessary to remind you about the well-known matter that every person has a mitzvah with which they must be especially careful; this mitzvah serves as the gateway for the elevation of their prayers and requests, as well as the channel for drawing down blessings needed for themselves and their family. In your case, this is the holy work in the Yeshivah founded by my revered father-in-law, the Rebbe zatzal. The more you increase your efforts in this area, the more all of the above will increase for you and your family both materially and spiritually.
With blessings to hear good news regarding all of the above and for a kosher and joyous Pesach for you and all your family.
Summary
The Rebbe teaches that each person has a unique mitzvah that opens channels for blessing. By dedicating oneself to their special role—in this case, work in the Yeshivah—one brings increased spiritual and material good to themselves and their family.