Midrash sur Les Psaumes 104:8

They fled, but they did not know where to flee, as it is said: The mountains rose, the valleys sank down, unto the place which Thou hast founded for them (ibid., v. 8). This may be compared to a slave whose master commands him to wait for him in the market but neglects to tell him where to wait. The slave asks himself: “Perhaps my master meant that I should wait near the basilica, or the bathhouse, or the theater.” When they finally meet, the master slaps him on the face, and says: “I sent you to the gate of the duke’s palace.” Similarly, when the waters heard the decree, Let the waters underneath the heavens gather in one place (Gen. 1:9), they did not know whether (they were to go) to the north or the south. And so, they raced about, as it is said: The mountains rose, the valley sank (Ps. 104:8), until the Holy One, blessed be He, struck them, and declared: I ordered you to assemble at the place of the Leviathan, as is said: There go the ships; there is the leviathan, whom Thou hast formed to sport therein (ibid., v. 26).