What are the implications of "Atah u'Vincha u'Ven Bincha"?
Seforno: If you, who witnessed all the great deeds that Hashem wrought in the desert, will transmit them to your children and grandchildren, who did not, then they too, will fear Him.
What are the implications of "u'Lema'an Ya'arichun Yamecha"?
Seforno: It means that you will all earn life in the (everlasting) world to Come.
Targum Onkelos and Targum Yonasan: It means that you will live long in this world.