Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 9: Conversation Between Sumantra and Daśaratha
Text 1.9.5

द्वैविध्यं ब्रह्मचर्यस्य भविष्यति महात्मनः।
लोकेषु प्रथितं राजन्विप्रैश्च कथितं सदा॥

dvaividhyaṁ brahmacaryasya bhaviṣyati mahātmanaḥ
lokeṣu prathitaṁ rājan vipraiś ca kathitaṁ sadā

dvaividhyam = will be contested; brahmacaryasya = brahmacarya; bhaviṣyati = it will be; mahā-ātmanaḥ = that this great soul’s; lokeṣu = amongst the populace; prathitam = well-known; rājan = O king; vipraiḥ = by the brāhmaṇas; ca = and; kathitam = described; sadā = always.

O king, it will be well-known amongst the populace and described by the brāhmaṇas that this great soul’s brahmacarya will be contested.

Another meaning of this verse is: “The brahmacarya of this great soul will be of two kinds as described by the authors of the Dharma-śāstras—(1) that which is well-known in the worlds as brahmacarya with total abstinence, characterized by its practitioner wearing a belt of straw, garments of deerskin, a rod and so on, and (2) that which involves engaging in sexual activity [only with one’s legitimate wife only] during her fertile season [only for begetting children].”

NOTE. The characteristics of the first type of brahmacarya are described in Śrīmad-Bhāgavatam 7.12.1-16. The above characteristics of the second type of brahmacarya can be gathered from the various Dharma-śāstra rulings for brāhmaṇas. The sage Yājñavalkya asserts that such a restricted householder is also a brahmacārī [1].

[1] ṣoḍaśa-rtur niśaḥ strīṇāṁ tasmin yugmāsu saṁviśet / brahmacāry eva parvāṇy ādyāś catasraś ca varjayet.