Bhagavad Gita 2.3
क्लैब्यं मा स्म गमः पार्थ नैतत्त्वय्युपपद्यते। क्षुद्रं हृदयदौर्बल्यं त्यक्त्वोत्तिष्ठ परन्तप॥
Easy meaning
Don’t collapse into helplessness — it doesn’t suit your strength. Leave small-heartedness behind and stand up.
When to use
Before a hard step you’ve been avoiding.