In response to your letter, in which you ask if you should accept the position offered to you by the principal of the school.

This decision depends on if your devotion is befitting such holy work. If it is, then 'ה's ברכות will dwell on it and as חז''ל say, יגעת ומצאת!

(From a letter of the Rebbe on ח''י כסלו תשכ''ו )