I could be wrong, but I believe it's from the TV 
series, the episode, "A wolf in the fortress" (I 
know I got the title somewhat wrong) but well, 
when Hotohori is saying after him and Nuriko 
rescue Miaka, he's saying when Tamahome is away 
he'll be the one to protect her. I dunno, they 
did an up-close shot of his face and that cel 
looks like the exact shot... Need to check your 
cel again, It is just a guess, a thougt. Not 100% 
sure...maybe someone can say for sure or not, 
just my thoughts. ^_^ Maybe someone can add to 
this or not, wanted to see what everyone else 
thought too.