Skandapurana 14.19.13

14.19.13

ekādaśyāṃ viśeṣeṇa karttavyaṃ snānamuttamam ..
dānaṃ kuryādyathāśaktyā sa yāti paramāṃ gatim .. 13 ..

On the eleventh day, especially, an excellent ritual ablution must be performed; / one should give a gift according to one's ability, and one attains the supreme state.