Genesis 9:13 New English Translation

¹³I will place^[a] my rainbow^[b] in the clouds, and it will become^[c] a guarantee of the covenant between me and the earth.

Genesis 9:13 tn The translation assumes that the perfect verbal form is used rhetorically, emphasizing the certainty of the action. Other translation options include “I have placed” (present perfect; cf. NIV, NRSV) and “I place” (instantaneous perfect; cf. NEB).
Genesis 9:13 sn The Hebrew word קֶשֶׁת (qeshet) normally refers to a warrior’s bow. Some understand this to mean that God the warrior hangs up his battle bow at the end of the flood, indicating he is now at peace with humankind, but others question the legitimacy of this proposal. See C. Westermann, Genesis, 1:473, and G. J. Wenham, Genesis (WBC), 1:196.
Genesis 9:13 tn The perfect verbal form with vav (ו) consecutive here has the same aspectual function as the preceding perfect of certitude.

New English Translation (NET)