“The sun will not transgress his measures. If he does, the Furies, ministers of Justice, will find him out.” (K 44; Cp. D, R, S 94)
Here Heraclitus is speaking of the measured order of the sun, moving daily from East to West but also annually in the solar year from Winter to Summer Solstice and back again.
The Furies were the children of the Earth (Gaia) and Sky (Ouranos). They worked at the bequeath of (Dike) Justice, the child of Zeus and Themis (or “law”) (Kahn 161).
Various partitioners of earth religions feared the sun not returning in its annual course. This in part explains the various Solstice rites and celebrations, meant to influence the gods to keep the sun and seasons on track. But Heraclitus accepts the view of Anaximander that justice and fate work, balancing oppositions “according to the order of time” (see Kahn, 161). Rites and rituals are not needed to preserve the order of nature. The sun tracks from the longest day of the year, Summer Solstice, to shortest, Winter Solstice, quite naturally in accordance with principles of cosmic justice. Were the rites and rituals abandoned, the sun would still not veer from course. Law-likeness and regularity are fundamental to the very nature of the cosmos.