Anandakanda 1.2.54

1.2.54

tato bhasma samādāya vāmahastena dhārayet /
naivādhaḥpatitaṃ pātre gṛhītvā gomayaṃ sudhīḥ //

Then, taking ash, he should hold it in his left hand;
the wise man, having collected cow dung that has not fallen to the ground in a vessel,