What do we learn from "Tif'eres Bachurim Kocham"?
Rashi: Just like the glory of youths is their strength, so "Hadar Zekenim Seivah."
R. Yonah: Hashem made everything nice in its time (Koheles 3:11). The glory of youths is when their strength is seen in them - Ben Sheloshim l'Ko'ach (Avos 5:21).
Malbim: Semen is the strength of the body. One who guards this strength and has Bi'ah only at the proper time, with the proper woman (his wife) and in the proper way, he will keep his strength in his youth. One who fervently pursues Arayos, he will lose his strength in his youth. One may glorify himself if he kept his strength in his youth!
What do we learn from "Hadar Zekenim Seivah"?
R. Yonah: The beauty of old age is white hairs, even though it shows that the moisture dried and the strength waned.
Malbim: If one has Bi'ah only at the proper time and way, old age will not come upon him prematurely. One who fervently pursues Arayos, old age will come upon him prematurely. It is glory when old age comes in its proper time, and not before!
