Agniveshyagrihyasutra 3.3.1.10

3.3.1.10

uttare 'vaṭe viśvedevayoḥ pādān prakṣāḷya madhyame pitṝṇāṃ dakṣiṇe pratasya pādau prakṣāḷya tānārādhya tāmbūlaṃ dadyāt \

Having washed the feet of the two [Brahmins representing] the All-gods in the northern pit, of the ancestors in the middle one, and having washed the feet of the newly deceased in the southern one, and having honored them, he should give betel.