Summary: Moses was living with God and living by God's word. He was so powerful man of God because of the encounter with God and His word.
Bible talks about three songs which were written and sung by Moses, one after Red Sea (Ex.15), second found in Ps.90, and the third is Dt.32. (31:19,30). It was a farewell song by Moses (31:24-25). He taught this song to Israelite (31:22) along with Joshua (32:44). The Theme of the Song was faithfulness.
Song starts with universe, praises to God (Deut.32:1-4). Israel’s unfaithfulness (v.5-6). The song proceeds to recite the history of Israel from bondage to occupation of Canaan (v.7-14). God will judge enemies (v.15-31). Then comes Compassion (v.32-42). End with joy (v.43).
This verse comes from this song. It talks about rain and dew. The Rains falls on the grown up and the dew on the tender herbs. God’s word is applicable to the children, youth, elderly. Its address the tender heart, harsh and rough heart. There is no end to it.
Moses was known for LAW, Commandments, and tit for tat but here he was expressing that his words were soft, tender, comfortable. He was not only received the Law, commandments, rules and regulations, even he receives the Gospel of Grace, Gospel of Love and compassion.
Book of Covenant includes and the rules are found from 20:22-23:19 apart from Ex.20.1-21 Ten Commandments.
Word of God Breaks:
The rain and the dew are liquids falling on the solid grounds of rocks, wilderness and the dry land. They break the rocks, wets the grounds and produces fruits and the crops, likewise the word of God is so powerful to break the hearts of the harsh and rough people, when the word of God received into the hearts of people it breaks them, makes them useful to them and to God.
Word of God Produces:
The rain brings life to the hidden plants and seeds. Rain and the dews make plants and trees to Grow and bear fruit. Moses claims that the teachings, doctrines are from God, for people. They were not his Own but God’s. Isa 5:6; 55:10, 11 also refers to the word of God as rains. The Word of God helps people receive grace, goodness and produces fruits and righteousness.
Joshua was courage (Josh.1:7-9), Gideon strengthened (Jud.6:14), David was comforted (1 Sam.30:8), Paul was motivated (Ac.22-23), Peter repented (Mt.26:75). Seed Produces 100-fold (Mt.13:23). Bearing fruit (Ps.1:3)
Word of God dwells:
The rain and dew are also reflecting the sun, after a heavy rain or the dew, you are able to see the drops over the grass in which you can see the sun, moon and stars. Likewise, the word of God dwells in any small person he will reflect the God of the Whole universe, God the almighty.
Dwells richly - Col.3:16 (by Read-Ac.17:11, Feed -Jer.15:16, sing-Col.3:16, speak with one another (Col.3:16)
May God bless you to meditate the Word of God.