Balancing responsibilities towards one's children with obligations to the community presents a significant challenge to all parents. Jewish communal leaders face constant conflicting demands on their time and attention, sometimes causing stress and tension. A remarkable interpretation of the K'sav Sofer sheds light on this age-old problem.
Nadav and Avihu brought before Hashem an unauthorized fire that He had not commanded them (Vayikra 10:1). The Medrash (Tanchumah Acharei 8) teaches that Aharon's two sons died because they did not marry in order to avoid having children. Another explanation of their sin offered by the Medrash is that they said regarding Moshe and Aharon, "When will these two elders die, and we will lead the community?" How can these explanations be reconciled with the Torah's explicit statement that they died because of an unauthorized fire? Moreover, how could such great tzadikim, greater than Moshe and Aharon (Rashi 10:3), sinfully avoid the mitzvah of procreation? Finally, how could they seemingly await the death of their father and uncle so that they should become the new leaders?!
The K'sav Sofer suggests that Nadav and Avihu saw that their cousins, the sons of Moshe, were not as learned and righteous as they could and should have been, and they feared that others might learn from this negative example. They attributed this development to Moshe's constant preoccupation with the community (see Rashi Shemos 19:14), which precluded him from raising his own children. By contrast, Aharon's children were great tzadikim, because he was not as preoccupied and raised his children properly. As a result of his greater involvement with his family, Aharon did not rise to the spiritual level of Moshe.
Based on this analysis, Nadav and Avihu concluded that as the presumptive future leaders, they would be unable to attend to the community properly if they would be busy raising children. Having children without the ability to raise them properly would cause them to go "off the derech." Therefore they decided, for the sake of Heaven and Am Yisrael, not to marry.
While the passionate fire of love for Hashem and His people motivated Aharon's sons, the conclusion they reached was mistaken; they should have married and not been deterred by the possibility of problematic children. Even Chizkiyahu's decision not to marry, which was based on prophetic certainty of bad children, forfeited his life in this world and the world to come (Berachos 10a). This well-meaning but nonetheless incorrect calculation was the unauthorized fire that Nadav and Avihu brought "before Hashem".
The K'sav Sofer asserts that Nadav and Avihu's attribution of sub-par children to a father's total preoccupation with communal matters is correct, and cites Shmuel hanavi as a case in point. His father, the Chassam Sofer (Toras Moshe Bamidbar 3:1), cites Moshe and his children as an example of this phenomenon. Moshe's absentee fatherhood was initially compelled by Hashem's command to go to Egypt, a place unsuitable for his wife and sons (Rashi Shemos 18:3). Moshe was even required, after matan Torah, to separate from his wife (Shabbos 87a). As such, Moshe's case is a unique one which is not a normative precedent for anyone else's decisions regarding family life.
However, Nadav and Avihu's assumption that Aharon did not reach Moshe's level because he was busy raising his children is not necessarily true. To the contrary, Moshe was chosen to be the primary leader precisely because of his devotion to the needs of others, even sheep (Shemos Rabbah 2:2).
The Meshech Chochmah (Bereshis 9:20) acknowledges that logically one who focuses only on his service of Hashem should reach a higher level than one who serves the community, as the Medrash (Koheles Rabbah 7:7) implies. Nonetheless, in a contrast noted in the Medrash (Bereshis Rabbah 36:3), we see that Noach, the ish tzadik who kept to himself, fell and became an ish ha'adama, a drunkard. Moshe, on the other hand, who had to flee as a result of his devotion to his oppressed brothers, at first was called an ish Mitzri [in the context of saving Yisro's daughters from the harassment of other shepherds] but later was elevated to be called an ish ha-Elokim specifically because of his devotion to Am Yisrael.
The rebbe of the Chassam Sofer, Rav Pinchas Horowitz (introduction to Hamakneh), comments on the requirement that a Rebbe be like an angel (Chagigah 15b based on Malachi 2:7) as follows: an angel is one who stands in place as opposed to people who walk and progress (see Yishayah 6:2, Zecharyah 3:7). Similarly, a rebbe must sacrifice his own progress to help his students. Rav Horowitz concludes that Hashem raises a rebbe to even higher levels because of his devotion. Thus Aharon became greater because he helped others, including, presumably, his children who were among his students (Eruvin 54b). Moshe was on an even higher level for other reasons, which included his devotion to others as well.
Prioritization in helping others has precedent in apportioning tzedakah: one's relatives have priority over others (Yoreh Deah 251:3). With respect to the tithing obligation, HaRav Moshe Feinstein (Iggros Moshe Even Hoezer 4:26:4) teaches that one must tithe one's time to teach Torah to others just as one must tithe one's money for tzedakah. By extension, educating and properly raising one's own children is a parent's first priority.
Clearly, each case of balancing family and community obligations has its own unique circumstances. We sometimes face difficult choices, and decisions must be made for the sake of Heaven. The above analysis provides some direction in making these decisions. If we fulfill the mitzvos and devote ourselves to others, hopefully Hashem will reward us, as in the past, by raising us to higher and higher levels.