Our Gemara on Amud Aleph raises the question: If the kohanim bless the people, who blesses the kohanim? Rav Naḥman bar Yitzḥak’s answer is that it comes from God’s promise to Abraham: “And I will bless them that bless you” (Genesis 12:3). All who bless the Jewish people are blessed themselves.

Be’er Mayyim Chaim (Shemos 25:2) explains this as an almost mechanistic function. Since you give the blessing, the Godly flow is channeled through you, and therefore you receive blessings too. Metaphorically, we can see it like someone who digs an irrigation channel through his field to another’s field. He will automatically benefit from the water as it flows through his field on the way to its destination.

Be’er Mayyim Chaim also draws a parallel between this and the principle taught by our sages (Bava Kama 92a): “Anyone who asks for compassion from Heaven on behalf of another, and he requires compassion from Heaven concerning that same matter, he is answered first.” Here too, when a person channels divine attention and, hopefully, his prayer is answered, the healing flows through him and riches him first,because he was the originator of that divine flow.

Regarding the concept that one who prays on behalf of another will be answered first, does it also require praying for the other person first? At first glance, one would think yes, because it shows a certain selflessness that itself is a merit. The Shalah (Torah Shenksav, Vayera, Derech Chaim 15) explains that the reason for this added merit is that it becomes the prayer of the many instead of an individual, since the concern is for other, and so there is more merit from that as well.

However, there is a liturgical proof to the contrary. We recite in the Brich Shmei prayer at the conclusion: “and fulfill the requests of my heart and the requests of the hearts of all of Israel.” Clearly, then, the prayer is for yourself first—even though the merit comes from praying for others.

How do we explain this discrepancy? Really, it is a verse in the Torah. By the order of the Yom Kippur sacrifices, first the Kohen Godol seeks atonement, then the Kohanic tribe, and then all of Israel (see Vayikra 16:17 and Horiyos 13a). The idea might be to achieve atonement for yourself first so that you are a better conduit for the blessing or the prayer.

One last thought based on this, having to do with a different blessing, is the traditional blessing fathers give their children on Friday night. If there is a grandfather at the table, not only should he go first out of respect, but also he should bless his child before his child blesses his grandchildren. This is because of the atonement effect we just discussed. A forgiven person’s prayer has more power and merit. I have not seen this discussed anywhere, but based on our above discussion, it would seem to be right.