Baba Sundar, celebrated for his six stanza composition, the Ramkali Sadu, incorporated into the Guru Granth Sahib, was the great grand son of Guru Amar Das. His father, Anand Das son of Baba Mohri, was a man of a devotion. Sundar grew up in an environment of spirituality and developed deep affection and reverence for Guru Amar Das, his great grandfather. The theme of his poem, Sadu meaning call, is the ascension of Guru Amar Das, described in terms of his having been recalled by God.

The hymn states how Guru Amar Das had completely surrendered himself to the Will of the Supreme Being, ever remaining absorbed in meditation on the Name of God, how he had, through the favour of Gurus, attained the office of Guru, how he, at the time of his departure, had appointed Guru Ram Das as his successor and how he had told his family to abide by the Will of the Lord and not to weep for him after his death.