Insensitivity to family: The Alter Rebbe admonished his son for being so engrossed in learning he didn't notice that his baby fell out of his cradle

In light of the discussion regarding Eiruvin (22a)  that a talmid chachom must be insensitive to his own needs and that  of his family - the following story raises questions. It is clear that the gemora in Eiruvin is not meant in an absolute sense. So what are the parameters? 

I would suggest that there is a constant obligation to be insensitive for the sake of Torah learning. However when a meis mitzva arises he must give up his learning until the mitzva is taken care of. In other words - Torah learning is the highest priority except in the face of a need which isn't being taken care of by others. Rashi says that one can be insensitive in providing food  - because G-d will provide. It would also following that if the wife or children can not accept living by bitachon - that this would also be a meis mitzva and the husband would have to give up his learning. However if the wife and kids can accept it - such as  the case of Rabbi Akiva's wife who accepted him leaving her for 24 years  - his obligation is to learn and not take care of his family.

Consequently the only reason the Alter Rebbe admonished his son - was that his son had accepted the responsiblity of watching the baby. It was a meis mitzva in regards to the son. Therefore doing anything other than the obligation to learn Torah is only a heter based on the immediate circumstances. Once the heter of meis mitzva goes away then the obligation of Torah learning is automatically reactivated

Chabad: Rebbe's Letters

By the Grace of G‑d
13 Kislev, 5723
[December 10, 1962]
Brooklyn, N.Y.

Greeting and Blessing:

I was pleased to receive the news of your forthcoming Dinner on the 20th of Kislev, the day after the historic Day of Liberation of the Alter Rebbe, Rabbi Shneur Zalman, author of the Tanya and Shulchan Aruch and founder of Chabad.

It is both timely and meaningful to recall the following episode from his life and teachings:

The Alter Rebbe shared his house with his oldest married son, Rabbi Dov Ber (who later succeeded him as the Mitteler Rebbe). Rabbi Dov Ber was known for his unusual power of concentration. Once, when Rabbi Dov Ber was engrossed in learning, his baby, sleeping in its cradle nearby, fell out and began to cry. The infant’s father did not hear the baby’s cries. But the infant’s grandfather, the Alter Rebbe, also engrossed in his studies in his room on the upper floor at the time, most certainly did. He interrupted his studies, went downstairs, picked the baby up, soothed it and replaced it in its cradle. Through all this Rabbi Dov Ber remained quite oblivious.

Subsequently, the Alter Rebbe admonished his son: “No matter how engrossed one may be in the loftiest occupation, one must never remain insensitive to the cry of a child.”

This story has been transmitted to us from generation to generation; I heard it from my father-in-law of saintly memory. It was handed down because of the lasting message it conveys, one which is particularly pertinent to our time. It characterizes one of the basic tenets of the Chabad-Lubavitch movement—to hearken to the cry of our distressed Jewish children.

The “child” may be an infant in years, a Jewish boy or girl of school age, fallen from the “cradle” of Torah-true Jewish education, or it may be someone who is chronologically an adult yet an “infant” insofar as Jewish life is concerned, an infant in knowledge and experience of the Jewish religion, heritage and way of life.

The souls of these Jewish “children” cry out in anguish, for they live in a spiritual void, whether they are conscious of this or feel it only subconscaiously. Every Jew, no matter how preoccupied he may be with any lofty cause, must hear the cries of these Jewish children. Bringing these Jewish children back to their Jewish cradle has priority over all else.