Kautilya's Arthashastra 2.11.60

2.11.60

guru snigdhaṃ peśalagandhi nirhāry agnisaham asamplutadhūmaṃ vimardasaham ity aguruguṇāḥ //

(Agaru is) heavy, soft, greasy, smells far and long, burns slowly, gives out continuous smoke while burning, is of uniform smell, absorbs heat, and is so adhesive to the skin as not to be removable by rubbing;—these are the characteristics of Agaru.