Shiva Purana
यदायदाभवद्दुःख देवानां ब्रह्मणान्तथा ॥ तदातदावतीर्याशु कुरुषे सुखिनो जनान् ॥ १४ ॥
When miseries afflict the gods and the brahmins you incarnate for the welfare of the people.
english translation
yadAyadAbhavadduHkha devAnAM brahmaNAntathA ॥ tadAtadAvatIryAzu kuruSe sukhino janAn ॥ 14 ॥
hk transliteration by Sanscript