Why didn’t Odysseus take his bow with him to Troy?specific location of answer

The answer to this question can be found in Book XXI.  I
cannot give you a page number because I do not know what edition of the book you might
have.

The basic answer is that the bow is too valuable to
Odysseus for him to want to bring it along to the war.  It is valuable as a keepsake --
for sentimental reasons.  This is because the bow was given to him as a token of
friendship by a man named Iphistus.  The bow had belonged to Iphistus' father who had
been killed by Hercules.  When Iphistus gave the bow to Odysseus, Odysseus was very
honored and therefore, later, he did not want to bring such a special bow to
war.

Here's a
quote:

This bow, then, given him by Iphitus, had
not been taken with
him by Ulysses when he sailed for Troy; he had used it so
long
as he had been at home, but had left it behind as having been
a
keepsake from a valued friend.