I lift up My hand to heaven: This way of speaking about God as if he had human actions (anthropomorphism; see study notes on 4:34 and 8:2) shows that God is serious about keeping his covenant promises to rescue his people from their enemies. When God makes an oath, he is not relying on any external force in case he fails. Instead, the statement emphasizes that God’s promises are completely reliable, beyond even his character (see Numbers 14:21, 28; Isaiah 49:18; Ezekiel 20:5–6).