The paths of their way are turned aside
That is, the waters, when melted by the heat of the sun, and the warmth of the weather, run, some one way, and some another in little streams and windings, till they are quite lost and the tracks of them are no more to be seen; denoting that all appearance of friendship was quite gone, and no traces of it to be found:
they go to nothing, and perish:
some of them are lost in little meanders and windings about, and others are exhaled by the heat of the sun, and go into "Tohu", as the word is, into empty air; so vain and empty, and perishing, were all the comforts he hoped for from his friends; though some understand this of the paths of travellers in the deserts being covered in the sand, and not to be seen and found; of which see Pliny F26.
F26 Nat. Hist. l. 6. c. 29.