[Buddha-l] Frightened bhikkhus

[Shantavira]

Is anyone familiar with a sutta in which some bhikkhus cannot meditate
because they are afraid in the forest, whereupon the Buddha teaches them the
metta bhavana? It's a story our author says she remembers hearing, but the
closest I can find is at S.i.219f (Sakkasamyutta 3) in which the frightened
bhikkhus are advised to recollect the Three Jewels.

Any ideas gratefully received by a frustrated copy editor.