אַתָּ֤ה פוֹרַ֣רְתָּ בְעָזְּךָ֣ יָ֑ם שִׁבַּ֖רְתָּ רָאשֵׁ֥י תַ֝נִּינִ֗ים עַל־הַמָּֽיִם׃
Thou didst break the sea in pieces by Thy strength; Thou didst shatter the heads of the sea-monsters in the waters.
Read kabbalistic (mystical) interpretation of Psalms 74:13: and classical mystical sources.