CC Ādi 5.29

yadyapi kevala tāṅra krīḍā-mātra dharma
tathāpi jīvere kṛpāya kare eka karma
Word for word: 
yadyapi — although; kevala — only; tāṅra — His; krīḍā-mātra — pastime only; dharma — characteristic function; tathāpi — still; jīvere — to the fallen souls; kṛpāya — by the causeless mercy; kare — does; eka — one; karma — activity.
Translation: 
Although His pastimes are His only characteristic functions, by His causeless mercy He performs one activity for the fallen souls.