Shankaracharya's commentary, trans. Alladi Mahadeva Sastry (1897)
[1]Whenever there is decay of righteousness and rise of unrighteousness, O Bharata, then I manifest Myself.
BG 4.7
यदा यदा हि धर्मस्य ग्लानिर्भवति भारत । अभ्युत्थानमधर्मस्य तदात्मानं सृजाम्यहम् ॥
yadā yadā hi dharmasya glānir bhavati bhārata | abhyutthānam adharmasya tadātmānaṃ sṛjāmy aham ||
"Whenever dharma declines and adharma rises — I project Myself forth. The divine responds to every crisis."
5 translations · all pre-1928 or released to public domain · sources
Whenever there is decay of righteousness and rise of unrighteousness, O Bharata, then I manifest Myself.
Whenever there is a decline of righteousness and rise of unrighteousness, O Bharata, then I project Myself forth.
Whenever there is a decline of virtue and an insurrection of vice and injustice in the world, then do I come forth.
When righteousness Withers away, and lawlessness uprises, O! then I draw Myself forth!
Whenever there is decay of righteousness, and there is exaltation of unrighteousness, then I myself come forth.