The Law Code of Yājñavalkya 3.1.41

3.1.41

nadīkūlaṃ tato gatvā śaucaṃ kṛtvā yathārthavat |
vastraṃ saṃśodhayed ādau tataḥ snānaṃ samācaret ||
sacailas tu tataḥ snātvā śuciḥ prayatamānasaḥ |
pāṣāṇaṃ tata ādāya viper dadyād daśāñjalīn ||
dvādaśa kṣatriye dadyād vaiśye pañcadaśa smṛtāḥ |
triṃśac chūdrāya dātavyās tataḥ saṃpraviśed gṛham |
tataḥ snānaṃ punaḥ kāryaṃ gṛhaśaucaṃ ca kārayet ||
iti ||

'Then, having gone to the bank of a river and performed purification properly, / one should first cleanse one's garment, and then take a bath. / Then, having bathed with one's clothes on, pure and controlled in mind, / taking a stone, one should offer ten double-handfuls for a Brahmin; / one should offer twelve for a Kshatriya; fifteen are prescribed for a Vaishya; / thirty are to be offered for a Shudra; then one should enter the house; / then bathing must be performed again, and one should cause purification of the house to be made.' / Thus.