6.3.86
चरणे ब्रह्मचारिणि
Operational rule vidhi
स is substituted for समान् before ब्रह्मचारिन् when it denotes persons engaged in fulfilling a common vow of studying the Vedas.
Word by word (padaccheda)
Right context चरणे saptamī · ekavacanaRight context ब्रह्मचारिणि saptamī · ekavacana
- Right context Saptamī (7th case): "when X follows", the operation applies to what precedes (1.1.66 तस्मिन्निति निर्दिष्टे पूर्वस्य). Also a condition or domain ("in the sense of").
Full reading
चरणे ब्रह्मचारिणि
Pāṇini leaves out words that carry over from earlier sūtras. Expand to see the rule as a reader actually understands it.
Commentary
स is substituted for समान् before ब्रह्मचारिन् when it denotes persons engaged in fulfilling a common vow of studying the Vedas.
Thus समानो ब्रह्मचारी = सब्रह्मचारी ॥ ब्रह्म means the Vedas. The vow of studying the Veda, is also called ब्रह्म ॥ He who is engaged in the performance of that vow is called ब्रह्मचारिन् ॥ समान refers to the vow, the vow of studying being common to both : i. e. समाने ब्रह्मणि व्रतचारी = सब्रह्मचारी ॥ According to Bhattoji Dikshit चरणे in the sutra means a शाखा or a department of Vedic study. He who has a common (samana) branch (charana) is a sabrahmchari.
Śrīśa Chandra Vasu, The Ashtadhyayi of Panini (1897), via ashtadhyayi.com.