Garudapurana 1.213.31

1.213.31

ubhayordve ca dātavye mūtraśaucaṃ pracakṣate /
ekāṃ liṅge gude tistrastathā vāmakare daśa //

And two [applications] must be given to both hands: this is declared as the purification after urination. / One to the penis, three to the anus, and ten to the left hand;