You uncovered your bow, you called for many arrows. You split the earth with rivers
NIV
Your bow was made quite bare; sworn to the tribes [of Israel] by Your sure word were the rods of chastisement, scourges, and calamities. Selah [pause, and calmly think of that]! With rivers You cleaved the earth [bringing forth waters in dry places]. [Exod. 17:6; Num. 20:11.]AMP
Thy bow was made quite naked, according to the oaths of the tribes, even thy word. Selah. Thou didst cleave the earth with rivers.
KJV