Agniveshyagrihyasutra 3.7.4.1

3.7.4.1

athaiteṣāmudakasapiṇḍānāṃ vāndhavānāṃ mātuśca yonisambandhebhyaḥ pituśca saptamāt puruṣādācāryāntevāsinośca sapatnīkānāṃ sāpatyānāṃ sapiṇḍānāṃ daśarātram \

Now, for these [kinsmen]—for the water-givers, sapiṇḍas, maternal relatives from maternal blood-relations, and for paternal relations up to the seventh generation, and for the teacher and his pupil, along with their wives and children—for the sapiṇḍas, [the impurity lasts] ten nights.