What does Psalm 103:7 mean?

The Lord revealed His ways to Moses, so that Moses could understand not only what the Lord was doing but also why He was doing it. Moses understood that God required His people to be holy because He, the Lord, is holy (Leviticus 19:2). He instructed Moses to convey this message to Israel. At Mount Sinai Moses prayed, "If I have found favor in your sight, please show me your ways" (Exodus 33:13). The Lord responded by showing Moses His glory and promising to be gracious and merciful (Exodus 33:19).

The Lord showed Israel His acts: His mighty deeds. We read in Psalm 78:12–29 about His miraculous efforts on Israel's behalf. God performed wonders in Egypt (Deuteronomy 6:22). He parted the Red Sea (Exodus 14:21–22). He led the Israelites by a cloud and a pillar of fire (Exodus 13:21–22). He gave them water from a rock (Exodus 17:1–6; Numbers 20:7–8). He fed them with manna and quail (Exodus 16:13–16). All these benefits from the Lord were reasons to praise Him.