The Ornament of Natal Astrology with Commentary

...[the lord of the house] belonging to a man has come under the influence of fire, they are burnt; therefore, they shall cause distress. Here, a single combination original: yoga of the four factors—the Lord of Wealth the 2nd house ruler and others—in a joyful state is not intended, because there is room for other interpretations when they are situated in a Difficult House Trika-bhavana: The 6th, 8th, or 12th houses, usually associated with challenges or loss. || 9 ||

Now, the author speaks of the Combination for the Loss of Vehicles Vāhana-virāma-yoga and the performance of their remedial rituals. The word "cruel" referring to malefic planets is implied here. However many Malefic Planets original: pāpagrahāḥ are situated in the House of Vehicles the 4th house and do not fall under the gaze of Benefic Planets original: śubha-vihaga, literally 'auspicious sky-goers', then:

As many malefic planets as are situated in the house of vehicles and are not within the sight of benefic planets, that is how many destructions of vehicles will occur for men, even those possessed of the highest qualities. || 10 || If cruel planets are situated in the Twelfth or Eighth House and look upon the fourth house, the wise should predict the same result. Truly, for these vehicles, a Pacification Ritual Śāntika: A ritual intended to avert misfortune or 'quiet' negative planetary influences should be performed by the wise. || 10 || If the Lord of the House of Knowledge the 5th house ruler is joined with Mercury and Jupiter but is located in a Difficult House, the man will be devoid of education. However, if that Lord is in the Ninth House, its own sign, or a Quadrant Kendra: The 1st, 4th, 7th, or 10th houses, the pillars of a chart, he will possess knowledge. If the planets are in a state of Infancy or Old Age original: bālatvaṃ vṛddhatā; planets have 'ages' based on their degrees in a sign at the time of birth, then men will have dullness of intellect; or if a planet is in its own sign, it may still be faulty. || 11 ||

The number of losses of vehicles will generally be equal to the number of cruel planets that cast their gaze. In such cases, the specific point is that a pacification ritual for the vehicles should be advised and performed by the wise. Thus ends the section on the Fourth House. || 10 ||

Now, describing the results of the Fifth House Pañcama-bhāva: The house of children, intelligence, and past merits, the author speaks of combinations for education and intellect. If the Lord of the House of Knowledge the 5th Lord is alone, or joined by Mercury and Jupiter, and is situated in a Difficult House the 6th, 8th, or 12th, then the person born is devoid of education. By the use of the word "or," it is suggested that even if the 5th Lord is in a difficult house, if there is a combination with Mercury and Jupiter, the environment is not favorable for education. However, if the 5th Lord is situated in the fifth house, the ninth house, or in quadrants, then the person born is educated. If joined with Mercury and Jupiter in such positions, what more need be said of his learning? i.e., he will be exceptionally learned.