Kāmadasutta

sn2.6:8.1 “Though it’s rough, hard to travel,

sn2.6:8.2 the noble ones, Kāmada, go on their way.

sn2.6:8.3 The ignoble fall headfirst

sn2.6:8.4 on a rough path.

sn2.6:8.5 But the path of the noble ones is smooth,

sn2.6:8.6 for the noble ones are smooth amid the rough.”