Bhagwad Gita
Chapter 2, Verse 69
या निशा सर्वभूतानां तस्यां जागर्ति संयमी।
यस्यां जाग्रति भूतानि सा निशा पश्यतो मुनेः।।2.69।।
What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.