Bhashya
सर्वं समस्तम् , खल्विति वाक्यालङ्कारार्थो निपात ।इदजगत् नामरूपविकृतं प्रत्यक्षादिविषयं ब्रह्म कारणम्, वृद्धतमत्वात् ब्रह्म ।कथं सर्वस्य ब्रह्मत्वमित्यत आह— तज्जलानि-ति, तस्माद्ब्रह्मणो जातं तेजोबन्नादिक्रमेण सर्वम्, अत तज्जम् ,तथा तेनैव जननक्रमेण प्रतिलोमतया तस्मिन्नेव ब्रह्मणिलीयत तदात्मतया श्लिष्यत इति तल्लम् , तथा तस्मिन्नेवस्थितिकाले, अनिति प्राणिति चेष्टत इति ।एव ब्रह्मात्मतयात्रिषु कालेष्वविशिष्टम्, तद्व्यतिरेकेणाग्रहणात् ।अत तदेवेदंजगत् ।यथा च इदं तदेवैकमद्वितीयं तथा षष्ठे विस्तरेण वक्ष्याम ।यस्माच्च सर्वमिदं ब्रह्म, अत शान्त रागद्वेषादिदो-षरहित सयत सन्, यत् तत्सर्वं ब्रह्म तत् वक्ष्यमाणैर्गुणैरुपासीत ।कथमुपासीत ? क्रतु कुर्वीत-क्रतु निश्चयॊऽध्यवसायएवमव गान्यथेत्यविचल प्रत्यय, त ऋतु कुर्वीत उपासीत इत्यनेन व्यवहितेन सम्बन्ध ।कि पुन ऋतुकरणेन कर्तव्य प्रयोजनम् ? कथ वा ऋतु कर्तव्य ? ऋतुकरण च अभि प्रेतार्थसिद्धिसाधन कथम् ? इत्यस्यार्थस्य प्रतिपादनार्थम् अथे त्यादिग्रन्थ ।अथ खल्विति हेत्वर्थ ।यस्मात्क्रतुमय ऋतुप्रायोऽध्यवसायात्मक पुरुष जीव, यथाक्रतु यादृश ऋतु अस्य सोऽय यथाक्रतु यथाध्यवसाय यादृङ्निश्च य अस्मिँल्लोके जीवन् इह पुरुषो भवति तथा इत अस्मा देहात् प्रेत्य मृत्वा भवति, ऋत्वनुरूपफलात्मको भवती त्यर्थ ।एव हि एतच्छास्त्रतो दृष्टम्—'य य वापि स्मर न्भाव त्यजत्यन्ते कलेवरम्' इत्यादि ।यत एव व्यवस्था शास्त्रदृष्टा, अत स एव जानन् ऋतु कुर्वीत, यादृश ऋतु वक्ष्याम तम् ।यत एव शास्त्रप्रामाण्यादुपपद्यते ऋत्वनुरूप फलम्, अत स कर्तव्य ऋतु ॥
In plain words
Everything is indeed Brahman. This manifest world, clothed in names and forms and perceived through our senses, has Brahman as its source—so called because it is the supreme and greatest reality. How can everything be Brahman? The scripture answers with the term 'Tajjala': because the entire universe—starting from fire, water, and food—is born from Brahman (Taj), dissolves back into Brahman in reverse order (La), and breathes and lives sustained within Brahman during its existence (An). Thus, unchanging across past, present, and future because nothing exists apart from it, this entire universe is Brahman alone. How this is one and non-dual, we will explain in detail in the sixth chapter. Recognizing that all this is Brahman, the seeker should remain peaceful, free from attachment and aversion, self-controlled, and meditate upon that all-inclusive Brahman with the qualities soon to be described. How should one meditate? By forming a firm resolve. Resolve is certainty and unwavering conviction: 'It is thus, and not otherwise.' This is the meditation enjoined by the text. What is the purpose of this resolve, and how should it be practiced? To explain how mental resolve is the direct instrument for achieving one's highest goal, the text begins with 'Atha khalu.' The phrase 'atha khalu' introduces a causal reasoning: a human being is made of resolve. Whatever kind of deep conviction and determination a person holds while living in this world, upon leaving the body at death, they become precisely that, reaping a destiny that mirrors their inner resolve. Scripture confirms this: 'Whatever state of being one remembers when leaving the body at the end, that is what one attains.' Knowing this established law of reality, the wise seeker must form the precise meditative resolve we will describe, for scripture guarantees that the fruit will match the resolve.
Close to the Sanskrit
All is complete, and 'khalu' is a particle for ornamenting the sentence. This world, modified by name and form, the object of perception and other means, Brahman is the cause, because of being the greatest, Brahman. How is theity of all Brahman? To that it is said—tajjala, because from that Brahman is born all, in the order of fire, water, food, therefore it is tajjaja, and in that same order of generation in reverse is dissolved in that very Brahman, being united as of its nature, therefore it is tallam, and in that same period of maintenance, breathes and lives and moves, therefore it is tani. Thus being of the nature of Brahman, it is undifferentiated across the three times, because of non-apprehension of any separation from that. Therefore this very universe. And just as this is one and non-dual, so we will explain in detail in the sixth. And because all this is Brahman, therefore being peaceful, free from faults such as attachment and aversion, controlled, that which is all Brahman, one should meditate upon that with upcoming qualities. How should one meditate? One should form a resolve—resolve is certainty, determination, 'thus it must be understood, not otherwise', an unshakable conviction, that resolve one should meditate, the connection is with the separated word 'kurvīta'. What is the purpose to be achieved by forming a resolve? And how should resolve be performed? And how is forming resolve an instrument for achieving the intended goal? For the purpose of establishing this meaning, the text beginning with 'atha' etc. 'Atha khalu' has the meaning of cause. Because a person is made of resolve, abounding in resolve, characterized by determination, a living soul, as his resolve is, whatever resolve, certainty of determination this person has living here in this world, thus departing from this body, having died, he becomes, meaning he becomes one whose fruit conforms to his resolve. Thus indeed this is seen from scripture—'whatever state one remembers abandoning the body at the end' etc. Since this arrangement is seen in scripture, therefore knowing this very thing one should form a resolve, such a resolve as we will describe. Since the fruit conforming to resolve is established from scriptural authority, therefore that resolve must be performed.