Sforno on Exodus 17:15/ספורנו על שמות י״ז:ט״ו

1ויקרא שמו, he called the name of G’d in his prayer ה' ניסי. The matter is similar to the prophet Jeremiah saying in Lamentations 3,25: קראתי שמך ה'. Surely, there was nothing new in Jeremiah knowing the name of G’d. The point is that he addressed this attribute of G’d in that prayer. Moses addressed the attribute of G’d as the flag-bearer in Israel’s wars.

2ה' נסי, “G’d is my exaltation.” The meaning is similar to Psalms 60,6 נתת ליראיך נס להתנוסס מפני קשט סלה, “You have given a banner to them that fear You, to raise themselves to its height before the might of wisdom.” In other words, the psalmist says that G’d will lend him the strength to cope with anyone trying to attack him and to overcome him. The same thought is expressed in Psalms 44,6 בשמך נבוס קמינו, “with the help of Your name we will vanquish those who rise up against us.”