Verse 3.15.2

तस्य प्राची दिग्जुहूर्नाम सहमाना नाम दक्षिणा राज्ञी नाम प्रतीची सुभूता नामोदीची तासां वायुर्वत्सः स य एतमेवं वायुं दिशां वत्सं वेद न पुत्ररोदं रोदिति सोऽहमेतमेवं वायुं दिशां वत्सं वेद मा पुत्ररोदंरुदम् ॥ ३.१५.२ ॥

tasya prācī digjuhūrnāma sahamānā nāma dakṣiṇā rājñī nāma pratīcī subhūtā nāmodīcī tāsāṃ vāyurvatsaḥ sa ya etamevaṃ vāyuṃ diśāṃ vatsaṃ veda na putrarodaṃ roditi so'hametamevaṃ vāyuṃ diśāṃ vatsaṃ veda mā putrarodaṃrudam || 3.15.2 ||

2. The eastern quarter of the chest is called juhū, the southern quarter is called sahamānā, the western quarter is called rājñī, and the northern quarter is called subhūtā. Vāyu [air] is the son of these quarters. He who knows this, that Vāyu is the child of the quarters, does not have to weep over the loss of his child. ‘I know that Vāyu is the child of the quarters. May I never have to weep over the loss of my child.’

Word-for-word explanation:

Prācī dik, the eastern quarter; tasya, of it [i.e., of the chest]; juhūḥ nāma, is called juhū [after the vessel used for offering oblations facing the east]; dakṣiṇā, the southern [quarter]; sahamānām nāma, is named sahamānā; pratīcī, the western [quarter]; rājñī nāma, is named rājñī [because the western sky is red in the evening]; udīcī, the northern [quarter]; subhūtā nāma, is named subhūtā [because those who are rich dominate this quarter]; vāyaḥ, air; tāsām, their [i.e., the quarters’]; vatsaḥ, son; saḥ yaḥ etam veda, he who knows this; vāyum diśām vatsam, that Vāyu is the child of the quarters; putrarodam na roditi, does not have to weep over the loss of his child; saḥ aham etam evam veda, I know this thus; vāyum diśām vatsam, that Vāyu is the son of the quarters; mā putrarodam rudam, may I not have to weep over the loss of my child.

Commentary:

The eastern quarter is called juhū because you face that direction when you offer that oblation in the sacrifice. The southern side is sahamānā because sinners go to that quarter to suffer the consequences of the sins they commit. The western side is called rājñī because when the sun sets in that direction, the sky becomes red.

Subhūtā is the name of the northern side, because it is dominated by Śiva, Kubera, and other deities of good fortune. Vāyu (air) is considered the child of the quarters because it arises from the quarters. If you believe that Vāyu is immortal and is the child of the quarters, you will then never suffer the loss of your child.