Flowed up the hill
The paradox reflected by this statement is connected intimately to a large amount of source material. The the human body is rendered as an amorphous shape, almost liquid, able to flow in the manner of water. Antithetically, the nature of the human river is directed against the compulsion of gravity, carrying upwards and cresting the hill rather than falling into compliance and rolling down its slope. In order to effectively attach to the slope, the human body would necessarily be able to establish some form of traction, of adherence that would anchor it and oppose gravitational motion. Bandelaine provides an explanation of this in the form of sap. The sap exists as a "flowing" lively entity that travels the veins of the human body, intermingled anatomically, a stark contrast to the dullness, the predictable patterns of an urban environment. Here, the same is true - the sap takes on a vivid life that resists the predictable motion of the slope, enabling the body to oppose constraints that challenge it. Additionally, Dante makes reference to the wicked souls that fling themselves from the shore, he compares them to autumn leaves falling away during seasonal transition. In this manner, the ejection of the damned into the belly of Hell contrasts vibrantly with common connotations of naturalistic deposition. Shedding of leaves demands lamentation, a mournful tone that encapsulates the loss of a thing that was living, was functional, was fertile. The passage of damned souls resides in opposition, evincing a position of security and justice - sinners are rightfully contained in Hell and represent a damaged vestige of humanity rather than a symbol of fertility. The sap's properties of viscosity and adherence harbor a similar notion. It is a remnant, a liquid that contains the lifeblood of nature, as is reflected by the leaves. However, it is employed in defiance of its customs - to aid the ascendance of humanity against nature's common laws.