Musar sur La Genèse 5:2

If one understands the deeper meaning of this commandment, one also gains an insight into the mysteries of Creation. We find a statement by Rabbi Eliezer in Yevamot 63 that anyone who neglects to fulfill the commandment to be fruitful is considered as having the sin of spilling innocent blood on his hands, the reason being that the Torah says in Genesis 9,6: "Whoever sheds the blood of man, by man shall his blood be shed." Since the Torah goes on to say : "Be fertile, increase, etc.," it is clear that failure to do so is considered a mortal sin. Rabbi Yaakov says: "Failure to try and have issue is a way of diminishing G–d's image in this world, since the Torah (still in verse 6 of this chapter) adds: 'For in His image did G–d make man.' Immediately afterwards follows the commandment to be fruitful." The Rabbis taught in Yevamot 64 that Numbers 10,36 ובנחה יאמר: שובה ה' רבבות אלפי ישראל, "When the ark came to rest, Moses would say 'return O Lord, You who are Israel's myriads of thousands,'" teaches that G–d's Presence is not found when Israel numbers fewer than 22000 souls." If Israel would number 21999 at any time and one of those Israelites failed to perform the מצוה of פרו ורבו, that person would be responsible for preventing the whole people from enjoying the Presence of the שכינה in their midst. We have now had three separate statements on the seriousness of failing to comply with the commandment to be fruitful. A) Failure to try and reproduce is equivalent to committing bloodshed; B) Failure to try and produce issue diminishes G–d's image in the world; C) Failure to fulfil this injunction prevents Israel from enjoying the Divine Presence in its midst. Prior to the statement quoted in the name of Rabbi Eliezer, the same Rabbi Eliezer is on record saying that a person who fails to marry is not an אדם, seeing that the Torah says of man (אדם) that "G–d created him male and female. He called their name Adam." (Genesis 5,2). You should appreciate that the statement of Rabbi Eliezer is to be understood as a general rule, whereas the subsequent statements are פרטים details, i.e. applications of the כלל. We must first understand Rabbi Eliezer.

Laban became aware of this, and this is why he protested in 31,43: הבנות בנותי, והבנים בני והצאן צאני וכל אשר אתה רואה לי הוא. "The daughters are mine, the sons are mine, the flocks are mine; all that you see around is mine!" I have already mentioned that we are called צאן while we are in exile. We also have scriptural proof for this from Psalms 44,23 נחשבנו כצאן טבחה, "We are regarded as sheep to be slaughtered." When we are on a high spiritual level, however, we are referred to as אדם, as we have shown. There is a difference, however, between אדם when referred to as a male, and between אדם when referred to as female. When G–d first created the human species, the Torah says of G–d's work זכר ונקבה בראם, ויקרא את שמם אדם. "He created them male and female, and He named them Adam" (Genesis 5,2). All the redemptions which we have experienced in the past have always been associated with the female element inherent in אדם; this is why our gratitude was always expressed by שירה חדשה, "a new song (feminine term) instead of as שיר חדש. When the redemption of the future materializes, however, we shall give thanks to the Lord with a שיר חדש, acknowledging the additional dimension of that redemption.