4:7  

यदा यदा हि धर्मस्य ग्लानिर्भवति भारत ।
अभ्युत्थानमधर्मस्य तदात्मानं सृजाम्यहम् ॥४-७॥

yadaa yadaa hi dharmasya glaanirbhawati bhaarata ।

abhyutthaanamadharmasya tadaatmaanaM sRRijaamyaham ॥४-७॥

Source: Automatic ITRANS Transliteration

Whenever there is a decline of integrity, O scion of Bharat,
A rise of corruption, then I manifest the Self.

Source: Milind S. Pandit

Source: The Bhagavad-Gita: The Sacred Song

Whenever and wherever there is a decline in religious practice, O descendant of Bharata, and a predominant rise of irreligion--at that time I descend Myself.

Source: Bhagavad Gita As It Is