It is due to Ignorance and Craving that one obtains this Body (Aggregates)

When we search for the culprit behind the aggregates, we find Ignorance (avijjā) and Craving (taṇhā). It is because of Ignorance and Craving that we have obtained this present body of aggregates. As long as this Ignorance and Craving are not uprooted, one will only continue to repeatedly obtain similar bodies. Because the body exists, one experiences various kinds of suffering: heat, feverishness, cold, chills, hunger, thirst, sickness, aging, pain, and death. One also cannot avoid mental dissatisfactions such as sorrow, lamentation, pain, and grief. All this suffering can only be pacified if the body does not exist. Therefore, if one desires and wants to attain Nibbāna—where there is no body, where all suffering is extinguished—one must practice vipassanā meditation. Ignorance does not know the Truth. Ignorance covers up the fact that the present body is the Truth of Suffering (Dukkha Sacca). One does not look at how the body is oppressing with wisdom, nor does one pay attention with mindfulness, so one does not get the chance to know. If one really looks to see, one will see suffering plainly. One suffers because of heat; heat is matter (rūpa), the aggregate of form (rūpakkhandha) is oppressing. One suffers because of cold; that too is the aggregate of form oppressing. When the heat is extreme, sweltering, and sweat pours out, that too is merely being oppressed by the water element (āpo dhātu), the aggregate of form. The suffering of the body and the suffering of the mind—physical pain and mental pain—also continue to oppress. Therefore, it is said that the aggregates are an oppressive phenomenon. It is called ‘khandha’ (aggregates) because it is a heap of such oppressive phenomena. As long as one is inseparable from this body, which is an oppressive phenomenon, the body will only oppress wherever it goes. It will follow and oppress in whatever existence it takes birth. Not knowing that it is oppressing now and will oppress in future existences is Ignorance—not knowing the Truth of Suffering. Because one does not know how the present body is oppressing, one cannot know that the future body will also oppress. Because of this lack of knowledge, one performs meritorious deeds wishing for a future body. Exactly as wished, one will only obtain another body that will oppress. One does not know that one currently possesses this oppressive body, and one also does not know that if one gets a future body, it will oppress. Therefore, striving to obtain a future body, to prosper in a future life, is all due to the ignorance of avijjā. Thus, it is said that one obtains a body because of not knowing the Truth. Not knowing present suffering and not knowing future suffering is Ignorance (avijjā). It is because of this Ignorance that one obtains a body. The present body was obtained due to the unknowing of Ignorance; because of that same unknowing of Ignorance, there is a continual desire and longing for a future body in the time to come. The desire to be a human or a deva in the next life is Craving (taṇhā). With that craving, one performs meritorious deeds for the sake of obtaining a body, wishing for prosperity as a human or a deva. Because Ignorance covers and Craving wishes (longs), kamma builds the house of the body, which is the Truth of Suffering. Just as past kamma built it, leading to the obtaining of this present body, so too in the future will it continue to be built. There is nothing else to obtain but the body, the Truth of Suffering. Not knowing, one wishes; because one wishes, one obtains the five aggregates, the Truth of Suffering. This body must accept heat when it comes, accept cold when it comes, accept the 96 kinds of diseases when they come. It is a body that accepts all kinds of feelings, an oppressive body. Although it is accepting and oppressive in this way, one does not know it as the Truth of Suffering. One is merely attached to and fond of the present body. One merely desires a future body like the present one. Because of this desire, one performs bodily and verbal deeds of generosity and virtue, making wishes. When the body is obtained exactly as wished, one has no respite, being enslaved to the body—feeding it, nurturing it, adorning it, dressing it, bathing it, and applying cosmetics. Furthermore, it will be oppressed by the dangers of aging, sickness, and death. Reflecting in this way, it becomes clear that it is the body, the Truth of Suffering. If one turns one's wisdom towards the body, it shows its oppression through heat, through feverishness, through cold, through pain and ache, through hunger and thirst, through sickness. It will show its oppression in countless ways. Just as it oppresses now, it will follow and oppress in whatever existence it takes. Because it incessantly oppresses like this, it is called the body, the Truth of Suffering. As long as the body exists, one must live with suffering. There is never a time free from suffering. This body, the Truth of Suffering, was obtained because of not knowing and desiring it. Not knowing is Ignorance (avijjā); desiring is Craving (taṇhā). Therefore, it is said that it is because of this Ignorance and Craving that it was obtained. Therefore, as long as this Ignorance and Craving are not eliminated, one will not be free from the body, the Truth of Suffering. Thus, only by destroying Ignorance and Craving can one be liberated from the cycle of suffering of the body. Ven. Dr. Parami