a heap: a mounded pile of loose material, most often harvested grain
Almost everywhere this word appears, it names a heap of grain: the mounded harvest on the threshing floor where Boaz lay down to sleep, the piled tithes of Judah that grew so large that Hezekiah and his officials blessed the LORD when they saw them, the grain heap in Haggai that a farmer expected to yield twenty measures but yielded only ten, and the lover's body likened to a heap of wheat in the Song of Songs. The picture is of a rounded pile of loose harvest, and in that setting a large heap is a sign of plenty and of God's provision.
One place uses the same word for a very different pile. When Judah's enemies mock the effort to rebuild Jerusalem, they sneer at the workers trying to raise living stones out of the burned heaps of rubble left by the city's ruin. The word itself is about the shape, a mound of heaped-up stuff, and the setting tells you what has been heaped.
Hebrew has other words for a pile that carry a fixed content: a heap of stones (גַּל), the long-standing mound of a destroyed city (תֵּל). This word leans toward the granary and the threshing floor.