Ramayana
नहि वेदितवान्मन्ये हनूमानात्मनो बलम् । यद्दृष्टवाञ्जीवितेष्टं क्लिश्यन्तं वानराधिपम् ॥ 7-35-12 ॥
I think Hanuman did not know his own strength, in that he watched the lord of the vanaras, dear to him as life, being afflicted.
english translation