In Matthew 6:33, Jesus speaks about having our needs provided for if we “seek first God’s Kingdom, and his righteousness” (WEB). In John 10:10, he also speaks about having come for his sheep so “that they may have life, and may have it abundantly” (WEB).
This same promise can be found in the Old Testament. The writer of the first Psalm compares the righteous man who loves God’s Word to “a tree planted by the streams of water, that produces its fruit in its season, whose leaf also does not wither” (WEB). But God himself declared this promise most beautifully:
It shall happen, if you shall listen diligently to my commandments which I command you today, to love Yahweh your God, and to serve him with all your heart and with all your soul, that I will give the rain for your land in its season, the early rain and the latter rain, that you may gather in your grain, your new wine, and your oil. I will give grass in your fields for your livestock, and you shall eat and be full. — Deuteronomy 11:13-15 WEB