Mahabharata — Anushasana Parva, Shloka 126
ज्येष्ठ-कनिष्ठ-धर्मः — Duties of Elders and Juniors
Anuśāsana-parva 108
नक्षत्रे न च कुर्वीत यस्मिन् जातो भवेन्नर: । न प्रोष्ठपदयो: कार्य तथाग्नेये च भारत
nakṣatre na ca kurvīta yasmin jāto bhaven naraḥ | na proṣṭhapadayoḥ kārya tathāgneye ca bhārata bhārata |
毗湿摩说道：“人不可在自己出生之宿（nakṣatra）行此祭礼；亦不可在两处普罗什塔帕达（即前后婆陀罗钵陀）之宿行之；同样也不可在火神之宿——昴宿（Kṛttikā）行之，噢，婆罗多。此教诲以择时为法的一部分：纵是功德之事，如祖先供献，也须依所定吉凶之宿而行。”
भीष्म उवाच
Educational Q&A
Ritual merit depends not only on intention but also on correct observance; certain nakṣatras—one’s own birth-star, the two Proṣṭhapadās, and Kṛttikā—are prescribed as unsuitable times for performing such rites (especially ancestral offerings).
In the Anuśāsana Parva’s instruction section, Bhīṣma continues advising Yudhiṣṭhira on dharma, giving specific calendrical rules about when particular religious rites should or should not be performed.