Valmiki Ramayana Sundara Kanda Sarga 48 Shloka 27

अप्रमेयः immeasurable, सः he, प्रवृद्धः increased, महारथस्य magnificent chariotwarrior, धनुष्मतः bowman, संयति in battle, संमतस्य efficient, तस्य his वीरस्य hero's, शरप्रवेगम् the speeed of arrows, व्यहनत् escaped, पितुः father's, मार्गे path, चचार went

Hanuman of immeasurable strength heaved himself to a huge proprtion and went moving on the path of his father (windgod) rendering useless the extraordinary speed of the arrows of Indrajit, who was great in chariot warfare, and an efficient archer.