Chapter-3, Sutra 40

Patanjali Yogasutra 3.40

(Spiritual Radiance)

समानजयाज्ज्वलनम्।

"By mastery over the Samana (a vital force), one gains radiance."

In this Sutra, Patanjali addresses the concept of gaining control over the body's vital forces, specifically focusing on Samana. According to yogic physiology, Samana is one of the five main pranas (vital energies) that govern bodily functions. It is primarily associated with digestion and the balancing of energy within the body, located in the region of the navel and associated with the digestive fire or agni. Mastery over Samana prana results in an enhancement of the body's metabolic and transformative capabilities, which Patanjali expresses metaphorically as jvalanam or radiance. This radiance refers to a heightened spiritual glow, physical vitality, and mental clarity that arise when one's internal energies are harmonized.

The term jvalanam - "radiance" - can also be interpreted on different levels. On the physical level, this mastery could bring about an increased inner heat or energy, which manifests as a vibrant glow or vitality in the body. On the psychological and spiritual levels, it suggests the illumination of Consciousness, where the mind becomes clearer and the individual is more attuned to spiritual wisdom and insights. Therefore, this Sutra underlines that through precise control over bodily energies, particularly 

Samana, one can enhance physical strength and spiritual power.

Moreover, this Sutra hints at a deeper yogic practice where the control over prana (life force) transcends mere physical benefits. When a yogi gains mastery over their prana, they attain control over both the gross and subtle aspects of their Being. The radiance here may be seen as an inner fire or transformative energy that is essential for higher states of meditation and Consciousness. This control facilitates spiritual awakening, making the practitioner more capable of withstanding distractions and remaining centered on the path of Realization.

Contextual Comparisons from Other Vedic Texts:

Brihadaranyaka Upanishad 5.9.1

असौ वा आदित्यः समयः। यः एष अन्तरहृदय आकाशः तस्मिन्नेयमात्मा ज्योतिर्भवति।

"The sun is indeed the external prana. The one who resides in the heart-space within, that Self becomes illumined by its own light."

This verse from the Brihadaranyaka Upanishad speaks about the concept of inner radiance or light that is Realized through the Self. Similar to Patanjali’s mention of jvalanam, this verse suggests that through mastery of inner energies and prana, one Realizes the internal light, which is an inherent part of the Self. This radiance is not just external vitality but a reflection of deeper spiritual illumination.

Mundaka Upanishad 2.2.10

तस्मिन्स्तु जितैन्द्रियः, उर्ध्वं ज्योतिषा उद्गच्छति।

"He who has mastered his senses rises upwards, radiating with light."

Here, the mastery of the senses leads to an ascension of Consciousness, with the practitioner glowing with Spiritual Light. This idea parallels Patanjali's Sutra, where controlling 

prana (specifically Samana) brings about a physical and spiritual radiance. Both point to the transformative effects of disciplined yogic practice.

Yoga Vashishta 6.1.18

यथा प्रभातसमये सूर्यस्योदयात् प्रभा। तथैव योगिनो देहे ज्योतिषां उदयो भवेत्।

"Just as at dawn the light of the sun rises, in the same way, the light of the yogi’s body arises."

The Yoga Vashishta compares the rise of spiritual radiance in the yogi to the dawn of the sun, emphasizing the connection between inner mastery and outward luminosity. This mirrors Patanjali’s concept, where control over vital forces like Samana leads to an enhanced spiritual glow or jvalanam. Both texts emphasize that through disciplined practice, one achieves a profound internal and external transformation.

These Vedic and Upanishadic verses, along with Patanjali’s sutra, consistently highlight the theme of inner radiance as the result of mastery over vital energies and senses. This transformation is seen as a sign of both spiritual progress and physical vitality. The comparisons reveal that controlling internal energies is a central theme in multiple Vedic texts, where it serves as a crucial step in the journey toward self-realization and spiritual awakening.