Additional Sessions Judge Ajay Kumar Jain gave city resident Kallu a week to furnish a bond of Rs 200 as a surety that he would not beg in future.
His sentence given by the magisterial court was modified by the sessions court on his plea for leniency.
He had come to Delhi thirty years ago as his house was damaged at his native village, the man had said.
The court said he has been detained in the rehabilitation centre since his arrest on August 9, 2012 from South Delhi and that was a sufficient period to make him "learn a lesson".
"Purpose of keeping a beggar out of the society has been duly served to large extent, therefore, I deem it appropriate that the sentence of imprisonment by way of detention in the Certified Institution be modified," the judge said, adding that the "appellant is released after due admonition".
"The appellant (Kallu) is duly admonished for the act of begging and it is further directed that after his release, he will furnish a bond in a sum of Rs 200 within one week as undertaking to the satisfaction of the magistrate that he will not engage himself in similar activity in future," it added.
The police had booked Kallu under the Bombay Prevention of Begging Act 1959 and had told the court that 52 rupees, received by him as alms from passerby were recovered from him.
