From Stormbringer, part one, where Pippin begs Merry not to turn him away.
Lots of reference used.
1) Fanart done by Kristin Bergh. Website is
http://www.kristinsstudio.com, you can find the specific pic in her gallery under "Nevi Publishing" and "Other Stories." I won't direct link because it zaps bandwidth.
2) Hand pose reference from a manga anatomy book.
3) Pippin's expression referenced from a manga expressions book.
4) Entire pic inspired by The History of Us: Stormbringer, part one by
daisy_gamgee