Shloka 5.1.167
समुद्रलङ्घनारम्भः — Commencement of the Ocean-Crossing
चकार सुरसा वक्त्रं शतयोजनमायतम्तव सानुषु विश्रान्तः शेषं प्रक्रमतामिति।तद्दृष्ट्वा व्यादितं त्वास्यं वायुपुत्रः सुबुद्धिमान्।दीर्घजिह्वं सुरसया सुघोरं नरकोपमम्।।।।सुसंक्षिप्यात्मनः कायं बभूवाङ्गुष्ठमात्रकः।
cakāra surasā vaktraṃ śatayojanam āyatam tava sānuṣu viśrāntaḥ śeṣaṃ prakramatām iti | tad dṛṣṭvā vyāditaṃ tv āsyaṃ vāyuputraḥ subuddhimān | dīrghajihvaṃ surasayā sughoraṃ narakopamam | susaṃkṣipyātmanaḥ kāyaṃ babhūvāṅguṣṭhamātrakaḥ ||
Surasā made her mouth a hundred yojanas wide, saying, “Rest upon my slopes, then proceed on your remaining path.” Seeing that mouth opened—long-tongued, terrifying, and like hell itself—the wise son of the Wind instantly contracted his body and became no bigger than a thumb.
Intelligent Hanuman observing Surasa's enlarged mouth open and dreadful like hell with a long tongue, suddenly shrunk his body to the size of a thumb.
Dharma is achieved through wisdom and restraint: Hanumān chooses a non-destructive, skillful solution—minimizing harm while fulfilling the condition of the test and continuing his righteous mission.
Surasā expands to an immense size and attempts to compel compliance; Hanumān counters not by force but by suddenly shrinking, preparing to enter and exit swiftly.
Practical intelligence (buddhi) joined to self-control: Hanumān’s ability to change size symbolizes mastery over self and circumstance.