The affix yat and ṭhañ comes in the sense of 'come thence' after the word pitṛ,
Thus पितुरागतं = पैतृकं or पित्र्यम् (VII. 4. 27.) and 6.4.148 'paternal -- i.e. wealth inherited from father.',
Adhyāya 4 · Pāda 3 · Rule 79
The affix yat and ṭhañ comes in the sense of 'come thence' after the word pitṛ,
Thus पितुरागतं = पैतृकं or पित्र्यम् (VII. 4. 27.) and 6.4.148 'paternal -- i.e. wealth inherited from father.',