1)
What is the significance of placing one's right hand on the head of the Bechor?
1.
Seforno: Placing one's hand on the person being blessed increases the Kavanah of the person blessing, 1 and the power of the right hand is greater than that of the left one. Consequently, leaning the right hand on the person on the right will elicit more Kavanah than leaning the left hand on the person on the left.
2.
Ha'amek Davar: There is more honor via the right hand, and the Berachah takes effect with greater influence.
1
Like we find in Pinchas (Bamidbar 27:23), when Moshe blessed Yehoshua.
