Parental death combination timing as per Jatak Parijat

 The verse is not merely describing yoga; it is describing a death-inflicting combination (anumarana yoga) based on the interaction of the lords of the Ascendant, 4th, and 9th. The underlying logic becomes clearer when the houses are examined from the perspective of each parent.

Rationale Behind Verse 77

Verse 77

मातृलग्नेशपितृपाः केन्द्रकोणस्थिता यदि ।
तद्दशान्तर्दशाकाले जनन्यास्त्वनुमृत्युदाः ॥

Meaning: When the lords of the Ascendant, the 4th house (mother), and the 9th house (father) are mutually connected by occupying Kendras or Trikonas, the periods (daśā–antaradaśā) of these planets may bring about the death of the parents, generally the mother first and the father thereafter.

Astrological Reasoning

This dictum rests on the maraka principles derived from the parental houses rather than from the native's own longevity.

Mother (4th House)

The 4th house signifies the mother.

• The 5th house is the 2nd from the 4th and therefore acts as the primary maraka for the mother.
• The 10th house is the 7th from the 4th, becoming another maraka for the mother.
• The 6th and 11th houses are the 3rd and 8th from the 4th, constituting the mother's longevity axis.
• The 3rd house, being the 12th from the 4th, weakens the mother's vitality and functions as a secondary (sah) maraka, especially when linked with the principal marakas.

Father (9th House)

The 9th house signifies the father.

• The 10th house is the 2nd from the 9th, making it the primary maraka for the father.
• The 3rd house is the 7th from the 9th, becoming the second maraka for the father.
• The 11th house is the 3rd from the 9th and the 4th house is the 8th from the 9th; together they form the father's longevity axis.

Why the Combination Becomes Dangerous

When the lords of the Ascendant, 4th, and 9th unite or are strongly connected through Kendras or Trikonas, they bind together the significators of the native and both parents into a single operative yoga.

The danger arises because:

• The 4th lord simultaneously represents the mother and the 8th (longevity) from the father.
• The 9th lord represents the father.
• The 10th house becomes a common maraka, being the 7th from the mother and the 2nd from the father.
• The 3rd house also becomes a common afflicting factor, being the 7th from the father and 12th from the mother, acting as a secondary maraka for the latter.

Consequently, during the daśā or antaradaśā of these interconnected lords, the longevity factors of both parents become simultaneously activated. Since the mother's maraka houses (5th and 10th) are generally triggered first through the involvement of the 4th lord, the classics state that the mother's demise usually precedes that of the father, followed later by the father's death when the same planetary chain activates the father's maraka houses (10th and 3rd).

Thus, the verse is not an arbitrary rule but a concise application of derived-house (bhavat-bhavam), maraka, and longevity principles to the parental houses.