Kautilya's Arthashastra 3.14.3

3.14.3

tasyavyayakarmaṇā labheta bhartā vā kārayitum //

A servant neglecting or unreasonably putting off work for which he has received wages shall be fined 12 panas and be caught-hold of till the work is done. He who is incapable to turn out work, or is engaged to do a mean job, or is suffering from disease, or is involved in calamities shall be shown some concession or allowed to get the work done by a substitute. The loss incurred by his master or employer owing to such delay shall be made good by extra work.

An employer may be at liberty to get the work done by (another) provided there is no such adverse condition that the former shall not employ another servant to execute the work, nor shall the latter go elsewhere for work.