Giani Daya Singh became the head of the Damdami Taksal after the departure of Giani Bhai Sant Singh to Sachkhand. He would deliver his religious discourse with the full customs and traditions of the Taksal and would teach the students the Gurbani and its meaning with explanations in the circumambuiation (Parkarma) of Sri Harmandir Sahib. After getting education from him, many people became preachers and Akhand Pathis and served the Sikh Panth in an exemplary manner. The foremost among his pupils is Giani Bhagwan Singh who has written exegesis or commentaries of the Gurbani and became the chief of the Damdami Taksal after him.
Once upon a time, son of Bhai Daya Singh committed a murder under the influence of bad company. The judges, who were supposed to deliver the justice, requested Bhai Daya Singh that to meet the ends of the justice his son deserves the gallows. But they would act upon the advice rendered by Bhai Daya Singh. But Sant Daya Singh said, "Do as the justice demands, do not put me inside this matter." When his son was hanged, he obeyed the God's will happily. He was so much attached with the God that he got detachment from his own son. With the grace of God he had already cast aside the false pride. So he called his daughter-in-law and said, “O my daughter! your husband is no more in this world. Now if you want the worldly pleasures you may go wherever you like, but if you want the perpetual benediction of the Satguru, unveil yourself, serve in the community kitchen, grind the flour, cook it and serve to the Sangat. This way you can be with us." Listening these words of Baba Ji, the daughter-in-law cast aside the false love with this material world and began serving the community kitchen. Not only his daughter-in-law but whosoever came into contact of Baba Ji, would be above the worldly pleasures and would start obeying the sweet will of the God.
Sant Daya Singh was a great worshipper and a pious saint. He observed the mode of living of a baptized Sikh. He preached the teachings of the great Gurus in his territory. With the result of his teachings innumerable people got themselves baptized i.e. took the eternal nectar according to Sikh traditions. In praise of Sant I I Daya Singh, people used to say that Aurangzeb might not have converted as many people to Islam with his sword, as the Baba might have done with his exemplary living and saintly preachings, towards Sikh religion. People used to address the Baba with most affectionate words.